Custom Skylight Frame Installation for a Van Conversion

You may be asking yourself:

What is that?

It's a custom-made steel tube frame for mounting a skylight to the roof of my van.

Why did he do that?

Natural light is super amazing, but I wanted to save some money by buying a cheaper skylight intended for mounting on a flat RV roof.

How did he do that?

I built the tube frame, cut the roof hole, welded the frame into the roof, painted it, caulked it, and installed the skylight.

How much of his lifetime was spent on building that?

Oddly phrased, but I spent about 42 hours building it. If you want to get into how much time I worked a job to raise the $310 I spent on the project, we could do that in the comments section.

Would he do that again?

Absolutely. The natural light is even more super amazing than I thought it would be.

Background

When planning my 2015 Ram Promaster van conversion, one of the first and most personally-important design features was to add a big skylight over the bed. Natural light plus privacy. It's not hard to drop some serious dough when shopping for skylights - most are high quality, some can open, a few have retractable sun shades. I decided to buy an outer dome for an RV skylight since it was quite a bit cheaper, and the bubble top is no doubt extremely cool. I got the biggest one that could fit in between the inner structural channels, which would roughly cover the rear half of the full-size bed.

This presented me with a problem: the roof of the van had a slight curve side-to-side, and the lengthwise ribs added extra weirdness. Searching the interwebs, I found articles where people had used fiberglass to help create a flat perimeter strip to mount the skylight flange to. This process also involved raising both ends of the skylight with butyl tape to combat the curvature before adding sealant. Sounded like some serious dinkin' around.

Although I kinda would've liked to level up my fiberglass skill, I chose instead to create a metal skylight frame that I dropped into the hole, welded to the roof, painted to match the van, and caulked inside and out. This provided a nice flat surface to mount the skylight to, additional stiffness, and the ability to replace the skylight easily in the future. I learned a lot along the way, and there are a few things I would do differently next time, but this project was 100% worth the time and effort. It looks incredible from the inside, and most importantly has performed well so far.

Table of Contents

Supplies

1. Construct Skylight Strips
2. Plan Tube Frame
3. Cut And Prepare Steel Tubing
4. Weld The Frame
5. Drill Pilot Holes For Skylight Screws
6. Trace Frame To Roof
7. Cut Out The Roof Cutout
8. File Hole For Optimal Frame Fitment
9. Weld Frame To Roof
10. Paint Frame
11. Caulk Frame
12. Install/Caulk Skylight
13. Admiration Of Skylight / Additional Tasks

These are the supplies and tools that I used - this framing method could apply to different styles of skylights, and some tools are not completely necessary, but very nice to have.

*optional tools (alt = alternative tool)

Supplies:

• ICON RV Skylight, SL1733C (37 1/2" x 21 1/2")
• Dicor Self-Leveling Lap Sealant, 10.3oz - x2
• Steel tubing, 2" x 1" x 0.065" - I needed 10' total
• Aluminum sheet, 3' x 1' x ~1/8"
• Automotive spray paint, color-matched, three-step process (get all three at an automotive paint place)
• Primer (good, solid automotive primer)
• Paint (have them scan your door to match the color, get TWO cans!)
• Clearcoat (must activate, mine had a 48hr potlife aka window of usage)
• Self-tapping screws, stainless steel, #10 panhead, 1" long - x30
• Fender washers, for #10 screw - x4

Power Tools:

• Jigsaw
• "Thin metal" blades
• "Very thin metal" blades
• *Pneumatic die grinder (alt: get these wheels for an angle grinder:)
• Cutoff wheels (alt: benchtop band saw, tin snips)
• Various wire brush wheels
• MIG welder (alt: TIG if you're fancy, stick if you're old school)
• Angle grinder w/ grinding wheel
• *Bench grinder (sometimes easier/faster than angle grinder)
• Drill (preferably cordless)
• Various drill bits
• *Chamfer bit (for deburring holes) (alt: drill bit, ~1/4" larger)
• *Drill press (alt: drill with skill)

Hand Tools:

• Flat file (the finer the better)
• Round file (^same)
• Hammer
• *Transfer punch set (alt: small regular punch, or sharpened nail)
• Wire cutters
• Steel wire brush
• Caulk gun
• Toothbrush (old, or your rival's)

Drawing and Measuring:

• Dixon Ticonderoga #2 pencil (w/ eraser)
• Straight edge ruler, 4-6'
• Square (L-shaped)
• Combination square ruler (alt: quick square)
• Level, 4-6'
• Tape measure
• *Digital/dial caliper (alt: get good at rulering)
• Painter's tape
• *Pencil sharpener (helps with tracing with a gap, explained later)

Misc. Tools:

• Step ladder, 8'-ish
• *A second step ladder (alt: move the first ladder around)
• Big plastic sheets (alt: garbage bags + tape)
• Quick clamps - x4 (alt: C-clamps)
• Right-angle clamps - x4 (EXTREMELY helpful for welding the frame)
• Wooden shims
• Shop light (magnetic is nice)
• *Headlamp (sometimes light is best projected from your third eye)
• *Carpet/foam square or knee pads (your knees will thank you)
• WD-40, or a similar lubricant (for cutting)
• Lacquer thinner
• Isopropyl alcohol, 70% or higher
• Paper towels
• Lint-free towels (alt: blue Shop towels, they're lint-free enough)
• *Stereo system or bluetooth speaker (for jams)
• *Coffee mug, filled with your brew of choice (PSA: light roast has more caffeine)
• Water bottle (clear pee is happy pee)

Personal Protective Equipment (PPE):

• Safety glasses
• Earmuffs
• Leather gloves
• Welding helmet
• Welding gloves
• Welding jacket and bandana (for welding overhead) (alt: old hoodie)
• Chemistry goggles (or any that make a good seal on your face)
• Nitrile gloves
• Disposable coverall suit
• Painting respirator for filtering ISOCYANATES (VERY important, automotive spray paints contain isocyanates)
• *Quote from above link: "[...] the recommended respiratory protection for employees spraying isocyanates is a supplied air respirator and not an air purifying respirator (i.e. filter cartridge style). The issue with use of air purifying respirators is that they will reach a point at which the filter becomes saturated and will no longer capture the isocyanate or other solvents."
• *Note: A fresh set of filters on an air purifying respirator (what I used) will probably be safe for the little bit of painting required (I never smelled it). This is what I did, but YOU are ultimately in charge of your own safety.

PPE:

• Safety glasses
• Earmuffs
• Leather gloves

The function of these strips is to distribute the force from each screw more evenly across the flange. I've heard that leak issues are most commonly attributed to a crack caused by the overtightening of a screw, so I decided to give myself some cushion. Worryin' ain't good for you.

I made four strips that spanned each side, but used fender washers for each corner (see Figure 1). If you want to go all-out, you could create a single-piece rectangular frame. A more relaxed version would be to simply use fender washers for all screws, which would probably be sufficient.

*First things first: make sure your skylight is undamaged from shipping and handling. Look for scratches and cracks, and make sure it sits relatively flat (on a flat surface). The flanges may contact on the inside but not the outside, but they'll get pulled down by the screws when installed. Keep the protective plastic on for now - you'll remove it after installation.

Measure the outer flange yourself (trust no one), and measure the screw hole size and test fit a screw. I had a few holes with a little plastic edge left over from the manufacturing process that I barely had to drill out so a screw could slide through. Draw and cut out your strips using a jigsaw with a blade for thin metal.

*Tips: While jiggin', use a slower oscillation speed to avoid melting the aluminum to the blade. Apply a squirt of WD-40 every inch or so before the aluminum starts clogging the blade - you'll feel the difference after the oil runs out. A less-messy method that can also work is using compressed air to cool the blade and remove the chips.

Afterwards, file the sharp edges with leather gloves on (gloves are cool). You can also add circular ends to each strip for a better grip on the skylight and steez points.

Indicate which direction is forward on the skylight using painter's tape. Decide which side each strip will attach, and mark each one accordingly. Who knows how symmetrical the screw holes are, so this ensures they line up later on. To transfer the hole positions, arrange the strips underneath the skylight, clamp it down, and use a transfer punch to mark each location. Check how they will sit on top, then re-punch each spot for a deeper indent. Drill each hole using a drill press so the screws slide right through. File all sharp edges (you look cool with gloves on).

I decided to make the frame 1/2" bigger than the outer edges of the skylight flange to leave space for a caulk bead, which worked well. Since the flange width for this skylight was 2", I chose 2" wide tubing, which combined with the 1/2" outer offset would leave a center hole that was bigger than the bubble area (for maximum bubblage - see Figure 2).

Using a level on the rooftop, determine the difference in height from the middle ribs to the outer valleys where the skylight will end using a caliper or ruler. This will drive the height requirement of the tube frame. In order to leave space for a caulk bead in the middle, you'll need extra height (see Figure 3). In the end, tube stock is much easier to get with certain dimensions, 1" x 2" being a pretty common size. As far as wall thickness goes, the thinner the better - no need to overdesign and add extra weight. I used 0.065" wall and it's pretty durn stiff.

*Note: I got my tubing from Metal Supermarkets, super cool place - they have many shapes, sizes, thicknesses, and types of metal in stock, and cut it to length for you. I bought a little extra just in case, which came in handy for having little scrap chunks to practice welding to the van's sheet metal. I rounded what I needed up to 10', but bought two 5' pieces to make transportation easier.

PPE:

• Safety glasses
• Earmuffs
• Leather gloves

*Note: Use a mitered corner design for strength and to eliminate open ends that would need to be capped. I would recommend marking and cutting one piece at a time to make sure each one comes out as close to its corresponding piece as possible. This will minimize the gap when welding, as a gap larger than 1/16" will increase the chance of blowing holes through the thin metal roof.

Mark the outside (longer) dimension and add the 45deg angles pointing inward (double check these are perpendicular to each other before cutting). Now would be a good time to double-check your skylight measurement to fulfill the "measuring twice" suggestion. If you're cool and own a benchtop band saw or miter saw, simply make the cut. If not, make the cut using a cutoff wheel of some sort, erring on the "too long" side, and grind the ends to be flat - make sure you keep to the 45deg line. File the edges for your safety (while wearing gloves, they really are so cool).

Repeat this process for each chunk, using the corresponding chunk to trace the lines. Again, take your time and err on the long side, as removing material is much easier to do than adding it. Afterward, arrange them in the 90deg clamps and check your measurements and gaps - grind/file them if need be to lessen the gaps, but don't remove too much material. Repeat until a deep satisfaction is achieved.

PPE:

• Safety glasses
• Welding helmet
• Welding gloves
• Welding jacket

Welding tips:

When welding a mitered joint, the progression listed below is great for minimizing any warping or movement. The heat created at a weld location wants to pull the two workpieces closer together. This is much more prevalent on the inside edge of a miter joint (basically a T-joint) - for this reason, the inside edge will be welded last. Additionally, the direction which you weld is also important to control this movement.

Welding thin metal presents the added challenge of avoiding blowing holes. As you weld, a pool of molten metal is created. If this pool gets too hot or too big, it can melt through the metal. Additionally, the arcing from the MIG welder can make the pool "pop", blasting a hole through the material. To avoid this, it's best to orient the tip so you're "pushing" your weld as opposed to "dragging" it - this will reduce the overall heat created and keep your tip directed away from the molten pool. For thin metal, there is no need to trace little circles while welding, as is common practice with thicker metal - move from point A to point B as fast as possible while creating a good weld, it will penetrate plenty. You also don't need to weld the entire length in one pass. Making shorter welds reduces heat, but only let up for about one second before starting again - this helps the new weld melt into the previous one. If you do blow through, relax and slowly fill in the hole using a series of short welds or tacks. Grinding will hide your mistakes!

To further reduce the amount of heat generated per joint, move from joint to joint between welds. This gives each joint adequate time to cool. If you experience lots of sputtering, try moving the tip closer to the metal - around 3/8" to 1/2" seemed to work well for me. A wire cutters is nice to have nearby to trim the wire length, but wait until the wire is cool to avoid damaging the cutting edges. If you have a large gap in your workpiece that you can't get rid of, you can use a nail to help fill the gap (it works well, trust me).

Before welding:

• Grind:
• Each upper and lower edge - 45deg, half the thickness (for good weld penetration)
• Each outer edge - 45deg, whole thickness (^same concept - see first three pictures)
• A lil' spot in the middle of a long side for the grounding clamp to attach
• Clamp the pieces in place and double check measurements
• Plug in the welder, turn on the gas, and turn on the welder
• Attach the grounding clamp to the lil' spot
• Set the welder to the correct settings for the thickness of metal you're working with
• Make sure there are no sharp bends in your electrode cable to ensure a smooth wire feed

Welding progression:

1. Tack each upper inside corner, followed by each upper outside corner, each lower outside corner, and each lower inside corner.
2. Weld each outer edge, starting at the top with the tip angled down.
3. Weld each upper edge, starting at the outside with the tip pointed inwards.
4. Flip the frame over.
5. Weld each bottom edge (now on top), again starting at the outside with the tip pointed inwards.
6. Finally, weld each inside edge.

• Here, I unclamped the frame and stood it up to create a classic horizontal T-joint, which I find easier than vertical welding.

After welding:

• Lay the frame flat to chill out
• On the upper edge, grind each weld area as flat as possible to create a nice surface to mount the skylight to
• Grind each outer edge to a nice fillet, file for a super smooth finish
• Clean the frame with a degreaser

In the end, caulk will help fill in and level out the seal area, so it doesn't need to be perfectly flat.

Pilot holes are recommended, as they help the self-tapping screws get started. They also allow you to feel the screw locations that are blocked by caulk when installing the skylight, ensuring that the skylight is perfectly positioned.

Mark one side of the frame as the front. Position the skylight on the frame accordingly and clamp it down. Lightly center punch each hole location and double-check that the location appears well-centered. Remove the skylight and re-punch each location again for a deeper indent.

*Note: The size of the pilot hole for self-tapping screws should be between the diameter of the shank (core) and the diameter of the threads, and depends on the material and thickness of the workpiece. I generally stick as close to the shank diameter as possible for maximum thread penetration, especially for thinner metal where less threads are engaged.

Fire up the drill press and drill each hole, only through the top surface. Afterwards, use a chamfer bit just to remove the sharp metal around the rims. A moderately larger drill bit also works well for deburring holes by hand.

*Tip: before climbing onto the roof, take note of the location of structural supports for the roof and try to only step/kneel there to avoid denting the roof. Cardboard also helps distribute the weight - my template for solar panels worked well.

The roof cutout needs to be as close to the outer frame dimensions as possible to minimize the gap for welding later, and a slight bow/warp on one side of the frame could mess with your mind, which is why you marked one side as the front. Test fit the frame on the inside and figure out where the hole needs to be, and make some marks.

*Important: keep in mind that you will need a little space around the entire frame on the inside to weld and caulk later. I used a leftover chunk of tube steel to get an idea of the location, and held the welder tip up to see how it would go. Remember that you probably want the tip less than 1/2" away from the area to be welded. I ended up skipping the high ribs and welding only the lower valleys because of this - the caulk will make these areas strong enough.

Measure to the rear marks from a reference point that is also visible on the outside, then replicate those marks on top. Find and mark the centerline of your frame and the van roof for side-to-side alignment.

Position your frame on the rear marks with the center aligned. Hold it down and trace around it, without worrying about marking the valleys at first. Once the ribs are all marked, trace down to the valleys as best as you can. A good way to achieve this is to sharpen your pencil with a pencil sharpener, hold the pencil so the sharpened angle is vertical and flush with the frame, and trace your line. Afterwards, you can sight down the line and adjust the valleys if necessary.

You might be wondering how you'll hold the frame up while you weld it. Simply sketch in a small 1" x 1" tab to the outer valley in each corner (the low points). This will vertically locate and support the frame while you tack it in, and you can cut them out later. Make sure you erase your previous trace lines and make it obvious so you don't accidentally cut out the tabs.

Double check the frame fitment and your measurements, then add painter's tape just outside the line. This will protect the van roof from getting scratched by the jigsaw base. A 2" strip should work for the straights, but you'll need a little extra around each corner since you'll be cutting curves - do some pretending with your bladeless jigsaw to see how much you need.

PPE:

• Safety glasses
• Earmuffs
• Leather gloves

*Note: I tried to avoid using a cutoff wheel on the van as much as possible. Compared to a jigsaw, these create more metal filings that are travelling at a higher velocity, and therefore get lost in the cracks and are quite the rust attractor. I used plastic sheets as much as I could for easy cleanup.

Jigsaw Tips:

Apply moderate, constant, flat pressure to the roof to minimize vibrations. Add painter's tape to the inside of the cut (ceiling) as you progress to support the cutout. If your jigsaw has a pendulum/rocking setting, I find that it works best for metal to have it set to straight vertical oscillation with no rocking. Use a blade meant for very thin metal. Move slow with a fast jiggin' speed to remove the smallest amount of material at a time (less chance of the blade catching).

Err on the side of making the cutout too small. The next step will involve hand filing the edges to ensure the tightest fit possible. This takes time but will make welding the frame to the roof much easier.

I had an interesting time cutting the final straight, which for me was the rear. The ribs prevented me from applying flat downward pressure, so the blade would violently grab the metal occasionally. To combat this, I would suggest saving the most supported length as your final cut, which for me was the front. I ended up shoving wooden shims wherever I could (more places for these in the front, too) and taping them to the ceiling to support the panel. You could also get a gloved, goggled, and earmuffed helper to support the panel, which I would highly recommend.

Pre-Jiggin':

• Tape up some plastic sheeting around the inside of the cutout to catch metal chips. You don't want these hanging around in the depths of your van attracting rust.

Jigsaw steps:

1. Drill a hole a bit inside your line that is big enough to fit the jigsaw blade through. If you want, you could triple-check the location of the hole inside and out to confirm your cutout is positioned correctly.
2. Time to get jiggy. Jig your way over to the inside of the line, and ride it to the end.
3. If you want to curve the corners a bit to match the frame, just think of the jigsaw as a grinder and work it around, then file it at the end. The arc is probably too small for the blade to cut smoothly.
4. The tabs are slightly annoying to cut out. You can curve in from previous cuts, and you can work the curve wider to make space for the blade to turn. Sometimes it's just easier to drill another blade hole. In the end, these don't need to be accurately-sized and pretty, so that's cool.
5. At the very end, I used a cutoff wheel to make the last couple cuts around the final tab, since the jigsaw would've bent the tab immediately. You could probably save all the weird tab cutout work for the end and use a cutoff wheel if you want.
6. File the edges with a flat file so you don't cut yourself (and wear those rad gloves, so awesome). Don't spend much time on this - you'll be filing much more in the next step.

PPE:

• Leather gloves
• Earmuffs

*Tips: Before doing any more filing, test fit the frame and see how it fits. You can make little trace marks using a pencil with the frame to note each spot that needs filing and roughly how much to file. Erase each mark after filing that spot so you don't get confused the next time you test fit and mark. Use a light from below to help contrast the contact spots and gaps. Again, the tighter the fit, the better. This step is the most tedious - put on some chill jams and take your time.

Assuming your cutout is too small on all sides, I found it easiest to follow this progression:

1. File the short sides until the frame fits between them.
2. Butt the frame up against the rear edge, and file the "high" spots until you have a decently flat edge (the frame should not entirely fit in the cutout yet).
3. File the front edge until the frame fits in.

Ideally, you shouldn't be able to move the frame around much at this point, but it's ok if it does a little.

PPE:

• Safety glasses
• Welding helmet
• Welding gloves
• Bandana or hood
• Painting respirator (the old paint will burn off, stinky in an unhealthy way)

More welding tips:

Now you'll be welding a thicker piece of metal to a pretty thin sheet (about half the thickness). In order to get good penetration, you'll want to set the welder for the thicker material. The basic idea is to direct the heat/wire at the thicker material, build up a little pool, and draw the tip up toward the thin roof until it just contacts and penetrates. Luckily, gravity is on your side and will pull the pool away from the thin metal, so stay confident. You don't need to weld the entire perimeter, just occasional tacks. I did completely weld the lowest valleys where the tabs were, but probs wasn't necessary.

Now that you have a fresh piece of scrap sheet metal from the roof, tack a leftover chunk of tube onto it from the "top" and practice welding from "below". Remember to grind a little spot for the ground clamp to attach. I set up a little support so I could crouch underneath and simulate the real thing. I burned through once or twice, but quickly became optimistic of this step going relatively smoothly.

Before welding:

• Using a wire wheel attachment, grind little spots for the tack welds around the edges on the inside
• I kept mine about 3/4" to 1" apart on the short flat edges, which was plenty strong. For the long edges, I would recommend grinding three spots on each valley and skipping the ribs if possible - the ribs are harder to weld, and the connection will be strong enough as is.
• I decided not to grind the rooftop paint off, but this might help avoid burning the old paint off. If you do, keep it thinner than a bead of caulk (about 1/4").
• Fit the frame in the cutout and double-check how it sits from the inside and outside
• Is it relatively level with equal amounts of light shining through? Does it wiggle up and down? If so, play with the tabs a little until it sits well.
• Open some windows and get a fan going for good ventilation

Welding progression:

1. Add a tack or two around each tab.
2. Add tacks in the center of each length.
3. Making multiple passes around the frame, add tacks that split the distance between existing tacks until all spots are tacked (again, to let each area cool).

After welding:

• Wire brush the weld area, and remove any attached chunks of wire or spatter
• A screwdriver works well for the smaller dots, and a hammer and chisel for the big blobs
• Clean the inside weld areas with lacquer thinner
• Use a toothbrush to clean the little crevices around the tack welds

PPE:

• Safety glasses
• Chemistry goggles
• Painting respirator (designed to filter isocyanates)
• Nitrile gloves
• Disposable coverall suit

*PPE is very important for this step. Google "isocyanate poisoning" and you'll want to invest in an approved mask and take the time to protect your skin. Ventilate that room!

Terminology:

• Flash-off Time: Amount of time required for the solvents in the paint to evaporate. Typically, additional coats may be applied afterwards. Trapping the solvents can lead to various quality issues.
• Tack-free Time: Amount of time until the paint is no longer tacky/sticky (longer than flash-off time). Usually, the next paint product may be applied afterwards.
• Back-taping: Creates a softer paint line than normal taping. Rather than creating a "hard line" with tape, position your plastic to cover the to-be-painted area, tape it down, and fold the plastic back - the "wave" of tape creates a softer line due to slight overspray.

First, use a wire brush or wire wheel attachment to remove the bubbled, yellowed paint on the rooftop weld area. If you did this before welding, you hopefully won't have to do too much more.

*Tip: I recommend keeping the grind area as thin as possible - later, you'll caulk over the line between new and old paint to better hide it.

*My mistake: I decided to grind the paint off about 1/2" away from the frame in an attempt to blend the paint, which didn't quite work out as planned.

Next, clean the area with isopropyl alcohol using a lint-free towel (don't forget the toothbrush). Apply painter's tape and plastic to the edges of the area. This includes the inside - primer dust was my main concern (it's annoying), and I didn't care too much about getting paint on other areas of the ceiling. Afterwards, I was able to just sweep off the plastic, remove it, and shake it out.

*Tip: If your ground areas are small enough to hide with caulk, tape as close as possible. If not, back-taping can help, although the ribs prevented this from working as intended. Additionally, step out the tape slightly between primer / paint / clear to ensure complete coverage.

*My mistakes: I decided to try and hide the line between new and old using existing features like the ends of ribs, which worked pretty well. In the front, however, no such features existed nearby, so I tried to blend the new and old paint by back-taping and stepping out each layer. However, I forgot to step out my paint from primer, and ended up with a fine gray line. Because I only bought one can of white paint, I was frantically shake-spraying the can at the very end just trying to finish painting the whole skylight, so I didn't have enough to cover my mistake.

Now open some windows, turn on a fan, shake that can for about 2 minutes and get sprayin'. For each coat, start on the inside and end with surfaces that you want the best finish on - overspray will make the surrounding surfaces slightly rougher. When painting, hold the can about 6-8 inches away and keep it in constant motion to avoid drips. Never spray with a stationary can, unless it's a very short burst from a distance.

Painting Progression:

• Primer
• 3 coats for crucial areas, 2 for non
• Flash-off = 5-10 minutes
• Tack-free = 30 minutes
• Paint
• 2 coats for crucial areas, 1 for non
• Flash-off = 5-10 minutes
• Tack-free = 30-45 minutes
• Clear
• 2 coats for crucial areas, 1 for non
• Flash = 10 minutes
• Dry to handle = overnight
• Total work time = 2-3 hours

*Double-check the instructions on the can/website for your specific paint's flash-off and tack-free times.

Whew! That last step made me pretty nervous, to be honest. Now you get to peel off the tape (amazing). Admire your work, but know that not many people will ever see it, and understand that the main reason for paint is protection and durability. Nobody cares!

Cut the tip of the caulk tube on a 45 degree angle with however large an opening you want (determines bead size). Clean the to-be-caulked areas with rubbing alcohol. Caulk the inside and outside edges, harnessing the confidence of the Dicor man.

*Tips: Try to put down as even of a bead as possible without trapping air. Have a dish of dishsoapy water handy for smoothing the bead with a damp finger, which also helps to force the caulk deeper into the cracks. You don't want too much water on your finger - any water caught underneath can cause bubbles. If you do get bubbles, pop 'em and splooge some more caulk in there. Watch out for drips when caulking the ceiling - smooth the caulk and keep an eye on it for an hour or so until it hardens enough. Isopropyl works well for cleaning up any accidents.

If you want, you can put a second layer on after it has hardened enough, which could take a few days depending on the temperature and humidity. This caulk stays sorta soft, but it's firmer than when fresh, and shrinks down a bit. Regardless, look for and pop any additional bubbles from the first bead and fill 'em in.

Remember that plastic covering on the skylight? If you left it on as instructed, good job, but right now you should carefully trim it up so it doesn't cover the flanges where you'll be working.

I recommend waiting until the frame caulk has hardened so you don't accidently touch it and mess it up. Get that isopropyl back out and make sure the frame and skylight flange are clean. Check that you'll have enough caulk before you get started (I would say over a half-tube, but don't quote me).

Installation Progression:

1. Put down a nice, fat, even bead on the frame right along the screw holes.
2. Carefully set the skylight in place in the correct orientation. Press down to squeesh the bead, working around the flange.
3. Add another fat bead under each strip length and at each corner, and place each strip/washer on top.
4. Install all self-tapping screws without tightening (no contact with surface). Then, snug the center screws with a screwdriver, moving outward to each end to ensure even clamping. Go easy on the first pass, then come back through once or twice more and slowly tighten each screw fully. I recommend using a screwdriver, but a drill with a low chuck setting would work too.
5. Add a caulk bead around the outer edge of the skylight.
6. Caulk around each strip/washer and on top of each screw head.

Smooth each bead using a damp finger and let cure for a couple days, keeping an eye out for any bubbles that might show up. It's likely some caulk squished out on the inside, so clean that up as well before it cures.

The time has finally come to peel off that protective film and gaze through your creation. Take your time, but you should probably get back to work. Before moving on to your next task however, consider the following additional tasks:

• Simulate a rainy day to check if your caulk job was adequate.
• Add a nice frame to the inside, if desired. My frame consists of four wood planks with two blocks on the side of each long board for attachment to the bottom surface of the frame. The blocks also allow a furring strip to be attached for ceiling panels. I drilled eight additional holes into the frame and used self-tapping screws.
• I had the thought to add a sheet of polycarbonate underneath to create a volume of trapped air to help with insulation, but decided to hold off for now. Most RV skylights like this one are designed to have an inner piece installed for this purpose, but it blocks a lot of the actual skylight area. We will see how it performs without one.
• I will be making a window cover out of Thinsulate and Low-E insulation for cold nights or hot days. I'll have to add Velcro attachment points or hooks of some sort to hold it up. If this step is not addressed, the wall insulation will likely be for nothing, as most heat transfer occurs through windows.

Final Thoughts:

• Watch out for overhead branches when driving to avoid scratches.
• I hope this inspires or helps someone with their van conversion - the natural light is absolutely worth the effort. I'd love to see your completed project, along with any changes or modifications you've made.
• The building process is mentally taxing. Nightly waves of overwhelming stress, a seemingly endless list of tasks with an ever-changing order of operations, and the ever-present FOMO all take a toll. Call your friends, do some yoga, take a day for yourself and get outside, and know that the time invested will pay off.

Thank you for reading!