2003 Suburban 1500 Pop Top Conversion

rayra

Expedition Leader
Is all that pine a buck / mold for the fiberglass top, or is it intended to be glassed over and kept in place? If it's the latter I have to warn you that pine is a terrible choice, even kiln dried, it's going to warp and twist. You need something with a lot more dimensional stability, like birch plywood or something similar. Better yet, metal. Some aluminum plate would be ideal in several ways, weight, stability, corrosion resistance etc.
 

boll_rig

Adventurer
Is all that pine a buck / mold for the fiberglass top, or is it intended to be glassed over and kept in place? If it's the latter I have to warn you that pine is a terrible choice, even kiln dried, it's going to warp and twist. You need something with a lot more dimensional stability, like birch plywood or something similar. Better yet, metal. Some aluminum plate would be ideal in several ways, weight, stability, corrosion resistance etc.

Rayra, the plan is to cover it with 1/4" Birch but yes essentially its all intended to be glassed over. Do you really think I'm going to run into warping issues with this intended route? Anyone else agree here? I would have liked to have gone metal but I have always been much better at working with wood. Now if youre talking about just covering this frame with metal sheeting that is something I could do. Not sure where to go from here now. Thoughts anyone?

miniorf, lets do it!

On a better note, Canyonlands was incredible! Was actually my birthday as well, so we had a good little get together at one of my favorite spots that I found first on google earth, you can drive right up to this cliff and its all on BLM land.

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Drive in.
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Rally.jpg

Now I know I said I was gonna take it easier in the truck, but sometimes its just too hard to resist. This actually resulted in me getting very stuck. First drift around went okay, shoulda kept it at one. The second time I hit my same tracks and slowed way down and quickly sank in the sand. I also found out that my 4wd light goes on but it never engages. Not sure what the issue is but I only had one wheel spinning. Definitely need to get that looked at..
 

rayra

Expedition Leader
Sorry to say I do think there'll be trouble. Really think those long sides are gonna twist. There's just no good pine / fir anymore, the plantation stuff is fast-growth and just wants to twist all the time, especially in long runs Part of the likely trouble is the necessity of the design layout. Your cross pieces are necessarily flat to lend headroom in the final design, but that means there's nothing to keep those long sides from contorting, except the box framing you've done at the ends. I don't want to be a Cassandra about it, just saying it's a lot of work to go thru without building to avoid the trouble from the get-go.
I'd strongly suggest re-executing your design and using some 1/2" birch plywood [left that bit out], two layers on each side, glued and screwed to each other. If there's any bow to the sheet at all, flip one piece so they work against each other. A single layer will work for your cross pieces. They don't have to be very strong, especially if they are being glassed in.

I'm an amateur woodworker. I've done a lot of different things in a lot of different woods and I'm a cheap bastard. So I've made some of the mistakes I'm warning about.
Here's several pages of things I've built myself, just about all of it from my own designs / ideas, and a lot of web searches.

https://www.flickr.com/photos/rayra/
 
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Dratwagon

Adventurer
Is all that pine a buck / mold for the fiberglass top, or is it intended to be glassed over and kept in place? If it's the latter I have to warn you that pine is a terrible choice, even kiln dried, it's going to warp and twist. You need something with a lot more dimensional stability, like birch plywood or something similar. Better yet, metal. Some aluminum plate would be ideal in several ways, weight, stability, corrosion resistance etc.

I was going to address this over the phone but since it's been brought up, if it was me I would finish construction then use it as a buck, once you get enough layers on the outside pop it off the the buck then bend some 1/2" x3" thick Styrofoam as braces on the underside and cover with fiberglass, this method is just as strong as wood, look at the underside of a camper shell.

get yourself a good fiberglass repair book.
 

boll_rig

Adventurer
Rayra,
You have some beautiful pieces on your flickr! really nice designs too, I enjoyed browsing through them; may have even gotten an idea or two for a coffee table ha. And I appreciate the advice before I actually fully jumped into this. It has been a concern of mine from the beginning. I know that Derek used pine, or some pine, for a similar topper on an excursion and I kind of just ran with that.

At this point it seems like I have a couple options but would be open to hearing any others people have. First option would be, as you are suggesting rayra, to rework the wood frame with Birch ply, then glass over that and hope it doesn't warp.

Option two would be, as Dratwagon has suggested, to simply use my wood frame as a buck and go only fiberglass. I wanted to see what peoples thoughts were on here. One concern of mine is cost and if anyone has a rough estimate of how much they think it would be to make a durable all fiberglass shell, I'd love to hear it. Im guessing 2-4 hundred?? It seems I would be spending more than just fiberglassing the wood.

Another concern of mine is the extreme heat and cold that I am in. Summers in colorado can get extremely hot, and when traveling in the winter its not unlikely to be in -10 to -20 for nights on end. A few years of this and I can imagine how this thing will look with a wood core. Unless I were to fully seal both underside and outside with fiberglass. But that seems pricey, however could be an option.. I do have a garage here that I can keep the truck in for the most part but when im on the road thats not really possible.

Going all fiberglass has also got me wondering whether I would glass in my mounting brackets to the underside and whether that would be strong enough; or whether I would want to bolt them all the way through, and then seal those..Thoughts? On top of that, my original idea was to have the inside covered by a light, wooden panelling, possibly a cork board to be able to tack things into. Having all fiberglass I would need to either epoxy or bolt wooden runners below this to mount them, as well as to mount the LED lights and conceal the wiring. So, just a few reasons it would be a little less work to stick with the wooden frame. I suppose I could nix all ideas of making it cozy up there too hah.

Correct me if I'm wrong, but I also thought that if I were loading up the roof with my racks, then surfboards/snowboards and possibly a thule/cargo rack, that I would be better off keeping the wood frame. However, as Dratwagon is suggesting maybe I could make it just as strong by reinforcing the underside?? I would still want some solid oak or metal crossbars to mount the racks onto though.

Weight being the clear and overall advantage of the all fiberglass shell. I'd estimate that already the wood frame is 80lbs. After 1/4in ply and fiberglass could be 150-200 lbs. Im sure the lifts could handle that plus gear but would be nicer on my mounting points if it were lighter, especially considering high wind and off roading.

Im wondering if I were to keep the wood frame whether bolting that through the fiberglass would help it from a possible separation and/or warping down the road? Or whether it would just crack and become a messy situation?
Whatever route I choose, I can certainly redo later on if problems develop, not the end of the world. But getting this correct of the bat would be ideal.

Sorry for the excessive rambling post here, but wanted to voice some of the pros and cons in my head. Please chime in with a suggestion, method, or opinion on where to go from here. Much respect and thanks to you guys!

Dratwagon this ones for you:
BOOK012.jpg
Great read actually, about halfway through..
 

rayra

Expedition Leader
I would suggest using what you've done as a buck, with some modifications. Get some vertically oriented cross-braces in there now before the long sides can warp, Use the 1/4" ply skin you intended to close it all up. Use a router and a 3/4"? radius bit to round over all the edges. Use bondo to clean it up, make things smooth. Smoother and prettier the buck pattern is, better the glass will come out. clearcoat / resin glaze the buck for a smooth surface to pull the fiberglass off of. Be generous with the release agent before laying your glass.
Once you've pulled your fiberglass cap, treat it like a boat, and glass in some plywood stringers flat on its interior ceiling / bottom of the boat. Once that is all set, flip it all over and put another 2-3 layers of glass on the outside.
Figure your roof rack brackets and place those wood stringers accordingly, so you later bolt the rack thru the wood.
When you build the rack, use a continuous metal rail or foot in contact with the fiberglass shell to fully distribute the load, instead of only 6 or 8 foot pegs.

Didn't really look for it in the pictures, but did you cant the sides and ends any a la the classic Westfalia shapes? That will also help you when pulling your glass off your buck. Right-angle sides will make it a little tougher, but if you started with enough layers it's not really an issue. It's been a VERY long time since I fiberglassed anything, is there anything new and beneficial going on or is it still the same of itchy stinky mess?
 

Dratwagon

Adventurer
Go here read reread and look at all the pictures, I think that this would be good to copy, I like the two piece design, it will keep the noise down and is less likely to leak.
I still don't like the idea of using wood do to the fact that fiberglass and wood expand and contract at different temperatures.

There will be more as you get closer.

http://www.expeditionportal.com/for...op-grafted-into-it-also-dual-360-swivel-seats

rayra: amazing woodworking skills and that's coming from someone that was literally born into woodworking.:beer:
 

boll_rig

Adventurer
Dratwagon, I had been looking for that thread. Thanks for finding it. Love that design and the fabrication is really well done. Honestly though I think that I would want a little more room up top. Some great ideas for mounting though, as well as reinforcing my cut out roof. when and if i get there ha.
Right now I am leaning towards going all fiberglass and modifying my wood frame for a buck. Although redoing the wood frame with birch sidewalls and glassing that is not 100% out the door yet.

I recently talked to Derek about what he did with the Excursion and he said he did use birch sidewalls, like you suggested Rayra. That was five years ago and he said it had yet to warp, but who knows under what conditions the owner kept/used the truck in.
Just a bit of info I found interesting..

Anyone else have a thought?
 

Dratwagon

Adventurer
So you asked me how I would do it, I would get me some Styrofoam and build me a stationary cap for the front, build up the perimeter of the roof and glass it to the body and for the lid I would find me a used 8 foot fiberglass tonneau cover.
 

boll_rig

Adventurer
Hows it going guys.

Wow! sorry for the massive delay here. So I had a pretty intensive knee surgery in the middle of the summer after I'd been gone for two months. One trip included a solo motorcycle ride from Boulder to Portland in Back over 2 weeks, 3000 miles, just on my 883cc sportster. Incredible to say the least, ill see if I can find a photo....


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As for the past 3 months I have been trying to learn how to walk again.. sigh. I got a little work in after that so i wanted to put up an update.

So, after much consideration upon Rayra and dratwagons thoughts I have decided to use the wooden shell as a buck/mold for a finalized fiberglass top. I was able to get in a few days of work on covering the mold. But before I was able to do that I ripped the entire sun of gun apart, broke all the glued joints, and cut each rib down by about 3/4 of an inch. Before that I put in some cross supports on the bottom to keep that dimension correct, with those in I replaced the cut down ribs giving my sidewalls approximately a 4-5 degree angle inwards to help with popping the glass off.

Before covering with the 1/4 in birch ply I decided that I wanted to shim up the middle to give the roof some curve. My solution was this:

IMG_5102.jpg

Before laying ply i glued and drilled them tight.

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The next step was to get it covered. heres a photo of it partially completed with the racks resting up there for looks

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And a photo with the front finally covered. Starting to look more like it! But man were those curved cuts a pain in the a**! happy with the fit though.

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One thing that was immediately clear was that I could have certainly put a bit more curve on it, not very noticeable and Im not sure that little amount of bow will make it any stronger like I had hoped, say if I had some weight up there not on the racks. But it will have to do..

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And then finally got around to finishing the back. As you can see I didnt really leave myself much room here! I may have to push the whole thing forward a cm.

IMG_5127.jpg

So its coming along at a snails pace, but being so busy, attending to knee problems, and traveling so much I am happy with how it looks for now. Obviously the next step is to clean it up quite a bit and router all corners/bull nose edges etc. Sand, smooth and bondo.

On top of everything else and all the setbacks it turns out that I tore some cartilage in my wrist this winter on a fall and have to get a small surgery to fix it. That happens in about two hours actually... So Im going to take the next two weeks to keep thinking about this and planning the glassing stage. Hoping to get back to work with some help after that.

All thoughts welcome.
 
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boll_rig

Adventurer
So I wasnt able to do a ton of work one handed but I did make some progress over the last week or so as my wrist has finally healed "enough." I was able to belt sand all the corners smooth and all the rough spots and then I used wood filler to smooth out all the countersunk screws and mishaps, and afterwards sanded everything again.

Here, I was glueing the two sheets of 1/4 birch together from the bottom as well as the birch sidewalls. As you can see I probably should have used vertical cross beams because as much as I shimmed the top sheet ply, as in the last post, it pushed down an equal amount onto my flat laying 1x4s leaving me with less of a convex roof. At this point I am not too worried though, but would have been nice to know this was going to be a mold from the beginning as I would have constructed it quite a bit differently.
IMG_6265.jpg

And I finally decided to get rid of my "spoiler" for ease of glassing and to keep the look congruent with the vehicle.
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In order to get the exact same curve from the angled-out back piece, I tacked it at that same angle and traced that line to the new back of the roof, then cut it to fit. Notice the very advanced pencil roller.
IMG_6276.jpg

Fits pretty nice I would say... and I am really liking the new back a lot more. What do you guys think?
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So I strapped it down and headed up to Dereks shop, Colorado Camper Van, to take some measurements for my canvas but he hadnt realized I had yet to glass it and said the measurements would be slightly off so we just chatted for a bit. He told me that I would have a hell of a time popping my roof off the mold because my sidewalls werent 6-8 degrees angled in. He also said my mold needed a ton of work including a wooden flange at the bottom to pry off the glass... I drove away wondering what I had gotten myself into, but decided to head straight to Plasticare in Englewood where I was going to pick up my glassing materials. Along the way I decided that I would go ahead without the wooden flange and if worst came to worst I could just flip the whole thing when done and delicately cut out pieces of the mold till it would break free.

A few more photos of the mold on the roof.
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After about 2 hours at Plasticare I had decided on my plan:

3 layers of 8 oz cloth and one layer of 2mm thick core mat as the second layer, and the other 2 to finish it. I talked a long time with Ron at the shop and decided that with reinforcing the underside with wooden stringers, this might be strong enough. If not I can add more layers to the top. I like the core mat though because of the thickness and dont need to deal with the mess of normal mat.

Ron also suggested that instead of glassing, sanding, polishing then waxing the mold, I could cover it with mylar using spray tac, both on the top and 4 sides (5 pieces of mylar total), then connect them with large width packing tape. Then spray with a release agent and lay the glass straight onto that.. Has anyone who has glassing experience tried this? He said he's done it quite a bit and the fiberglass pops off fairly easy. I think that if I do a good enough job wrapping the mold so that there are zero tape "bundles" and overlaps around corners, then this might work.

I purchase about 5 yards of 60" wide mylar
24 yards of 38" wide 8oz cloth (which I plan to lay in 2 lengthwise pieces, overlapped by about 10 inches all the way down the middle of the roof)
Enough core mat to evenly cover the mold
System three epoxy resin w half gallon hardener (most likely will need more)
and some other materials for about $402.. Not bad considering Derek said his glassing company would need 7 grand to get a product from my mold.
IMG_6402.jpg

I am planning on glassing with the mold on the car and taping mylar to all sides of the roof where the mold will meet it to avoid epoxy on the paint.

I have a few concerns I am mulling over in my head and am also going to do some more planning and tape/mylar testing this weekend before I think about glassing but suggestions are always welcome!
 

chilliwak

Expedition Leader
What an awesome:Wow1: idea to put a top on a `Burb´ Mr Boll!:drool: You really have done a nice job on fabricating that top. Cheers, Chilli...:)
 

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