2003 Suburban 1500 Pop Top Conversion

[rayra]

Ah great, glad to see you going forward with this was half afraid I'd scared you off it. I missed the november update. Looks like you've got good info from the experts. I like the sloped side aesthetics, but I grew up looking at Vanagons, so that's what looks 'right' to me. Your style is just as good. yes, a straight wall mold is generally ungood, but it really isn't that hard to pop your cured glass off when it's something so very much bigger. It's more of a problem with much smaller smaller patterns where there's less give in the glass. On something as big as your top, the issue is trivial. I LIKE the glass guy's idea about a wrap. Mylar or even a 6mil tarp or that funky white vinyl boat storage wrap seems like a great idea. just DON'T SKIMP on the release application.

It's going to be very interesting, I hope it comes out nicely enough to maintain your enthusiasm. Keep in mind that just about anything is fixable and can be modified. That goes for glassing in stiffening elements or making the exterior smooth and pretty. And bondo can cure a lot of ills.

The rounder you make your buck edges, the prettier it will be, IMAO.

Have you figured out how it will seal to the vehicle, a soft rubber flange gasket on the glass top, or gasket to gasket? What sot of mechanism or framework will you use to elevate the top?

PAY ATTENTION TO TEMP AND HUMIDITY constraints when glassing, it's winter now. That may screw you up. You might want to do a test run on something small first. Get a buttload of 2" chip brushes and rollers. Get a GOOD particulate and chemical vapor mask and USE IT.

Good luck with your project. It will be pretty unique when done.

 

[boll_rig]

Slow but Steady

Chiliwak and Rayra, thanks for the comments and the advice. Always appreciated!

Rayra, in terms of your question I was thinking rubber gasket on the topper, but may potentially have to go rubber on rubber, depending on the seal. In terms of glassing I will post the progress in a minute but I have definitely been working out the kinks of glassing in winter. Although Im in a garage its still proving difficult, and I thought that the west systems number 1 hardener would work best with colder temps. It still kicked too fast and didnt give me enough time for layups so I switched to number 2.

So I pretty much just jumped into it without doing one test run and hoped for the best. But like you said, any mistake can be fixed. I will say that I could never have imagined how time consuming this would be haha. Glassing isnt quick! Heres a run through.

Mylar about to be laid out
View attachment 325248


I cut the mylar for the top and sidewalls, then used 3in wide gorilla packing tape to connect the pieces, wrapping the tape around the edges. Working the corners was a bit tricky, the whole thing was kind of like wrapping one giant pain in the a** present. Lots of cutting and folding. Took about 10 hours. I then had some help and hoisted the bad larry up onto the roof, like you guys suggested so that the finished product would fit as it should. In hindsight I should have used an electronic level to recreate the exact shape of the roof on the table. Glassing on ladders on my tip toes was horribly annoying. On tuesday I spent 14 hours standing up there. :REExeSquatsHL1: on top of it I dont have a vehicle to drive currently ha.



Next up was laying the cloth out. But before that I sprayed release agent liberally over the whole thing. Now that the first layer is cured I can already pull it slightly off the sidewalls, So hoping when thicker I can pop the whole thing off easily.
As I said I had to do the length of the topper in two pieces, overlaped by 10 inches. I made a few vertical cuts so it would fit nicely. The hardest part by far was getting the dang corners to stay down. Had about 4-6 tiny cuts and folds on each one.
View attachment 325247

I would wet down the top then smooth out the sides all the way to the roof. I then used a crude method of sharpie-ing the joint of the mold where it met the car to get my cut line. I then cut away the excess cloth and wetted all the way to the roof. The method works more or less to my surprise. Now I did cover the meet point on the roof heavily in packing tape so as to not epoxy the dang thing to the roof of the sub. Yet I didnt account for the slipperyness of the tape on tape. Just getting the buck to stay in place was a nightmare involving strips of duck tape and corner stoppers of rolled tape. Its now slightly epoxied up there but should break free with a small hit.





I was hurrying to get the second cloth down before the first gelled up. I think i just made the cutoff time and wetted out the overlap first to get the chemical bond.



Close up of the corner. This was the only area I had trouble with bubbles. I just sanded them down and tried to forget about them.


Had a small area that was giving me trouble with staying down. Another genius solution lol.



And the first layer down! Happy with how it came out. Ended up cutting and overlapping the cloth on the back due to the convex roof. really didnt want bubbles.



Fast forward two weeks I was gone for christmas and trips and I gingerly drove the car outside to sand (praying the topper wouldnt fall off). Unfortunately doing this mostly on my own takes forever. I would love to be able to do more than one layup at a time but its nearly impossible. Hoping that a solid mechanical bond will work. If I knew anything at all, as hindsight proves, I would have made a female mold! Live and learn. After sanding I washed it down then wiped it with acetone in preparation for the core mat that would go next.



More to come in the next post. I do have a question of how you guys get your photos to appear bigger? I have the dimensions at 1000x1500 and still below 400kb but they appear tiny. Thanks and replies welcome!!

 

[jscusmcvet]

Coming along great! Kudos to you.

 

[boll_rig]

Thanks John. So far so good with just a few little hiccups.

I have been scouring the internet for an answer for a while now and hoping one of you might be able to help me out. System Three says that their resins will chemically bond up to 72 hours with a recoat. From their site: "When this first coat is cured to at least a soft set tack free stage it can be recoated. Subsequent coatings applied at anytime between this soft set stage and 72 hours do not need to be sanded and will chemically bond."

I have been worried about only getting a mechanical bond on my layups. For the first one I had to leave for two weeks so was okay with sanding it. But for these subsequent layers (3) I was hoping this would be true and I wouldnt have to kill myself rushing and do one layer a day. I also hoped that my colder temps, around 60 degrees, would help slow the curing time.

Does anyone know if this holds true for all System Three products? Any help would be great!

I started laying out my second layer, the core mat, looks kinda like a thin carpet. Its 2mm thick and takes one heck of a lot of resin to wet out. So far I have used over 3/4 of a gallon and have covered 2/3 of the roof with it. My thoughts were that this would give the roof some thickness in between the cloth. Not sure how much strength it will add though.

I would liberally cover the previous layer then lay down the mat, then pour and wet ontop of the mat.


Generally happy with the fit. Its hard to tell from the image but the corners are made up of thin long stips of core mat to form to the curve. I then filled the crevices with thickened epoxy, using microballons. Not the best solution but I dont have any silica thickener.


I spent time prepping my core mat properly for the best fit and hopefully less sanding later. Currently just about to start putting the front together.


Any notes or advice on my process is always greatly appreciated! And if anyone has a clue on the longest time I can wait to recoat that would be awesome as well. I had always just assumed that after it was hard to the touch it was too late, so this new info from system three is throwing me for a loop.

Thanks

-Ian

 

[Bushcoat]

Looks great, coming along quite well I'd say!

 

[jscusmcvet]

Ian - I think you are on the righ track. My boat builds have always used more resin than I thought they would. Making sure you do not create a "starved" joint, or bond is essential tot he process... one starved spot and the integrity of the piece becomes vulnerable... so what that means is do not skimp, soak it in and follow the system three rec's. I have always used MAS epoxies, but I doubt there is that much difference... Your real resource may lie here:

http://forum.woodenboat.com/

Good folks who will answer your questions and I am quite sure have more experience with fiberglass than I do. When you are done... come to NC and do mine

 

[justbecause]

:lurk:

 

[boll_rig]

Thanks Bushcoat, like i said slow but steady!

John, I appreciate the wooden boat forum info though, some very experienced guys on there and a very good resource. I seemed to have figured out my time constraints and should be good to do next layups anytime before 72 hours, especially with my colder garage temps, and still obtain a chemical bond. I have been very worried about the weak joints and starved areas and have been laying down quite liberally to account for that. And John, I'll be right over to spend countless hours of confusing messy work for yours! In fact after this project I hope to take a very long hiatus from fiberglassing anything big!

 

[boll_rig]

A little more progress today.

Finally finished the core mat layup. And very glad to be going back to cloth. Cutting each mat perfectly and then dealing with slivers for the corners was difficult at best. Im still not sure if this was the best decision, to use the 2mm core mat in the middle of my cloth for thickness. I have a feeling that Ive added tremendous weight without necessarily adding the equivalent in strength. The benefit is that I was able to make nice cuts and will now not need to worry about my fit on the roof.


Still need to finish filling in the gaps between the slivers on the corners. Really dont want gaps that could trap air before my next cloth layup, but it does look nice.


Im somewhat concerned about the weight in the end and am almost thinking I may not need two more layers of 8oz cloth ontop of this? Perhaps one more layer would do?

Another option would be to see if I can pull if off the mold after the next layer and see how strong it is. A little worried about flexing differently if its not on the roof if I do go ahead and precede with the fourth layer but this thing already seems pretty rigid. Anyone have any thoughts? Could I get away with just one more layer?

On a side note, not sure if anyone knows this guy in Boulder but I've been following his progress everytime I see the truck. Really awesome design! Love how he cut out his cab so its all one "room". Thought id share.


Cheers!

 

[Dratwagon]

I wonder off for a while and you get busy.
First off I never had the time to wait between coats, I have always used the heat from the first coat to flash the next coat so I think that I would hit it with a grinder to ruff it up.
If your not using the wood buck then use as much glass as you can, it's not going to weigh any more than your original dry ingredients.
Looking good, if you have any air bubbles grind them out and fill with resin.

 

[rayra]

It's looking good / interesting. How much total height are you adding? Are you glassing in any sort of reinforcing metal frame, after it's off the buck? Something to attach the lifting mechanisms to?

 

[boll_rig]

Thanks for the replies Rayra and dratwagon. Ive been trying to get busy anytime i have a minute. Never enough in the day though.

Drat Im learning now that you are right on using more glass. I ended up doing a layup with the 8oz cloth then another with the 4 right after and should have gone with the 8 again because its definitely a little thinner than I wanted. I tried to do as many layups consecutively as I could, and would sand when I couldnt. And luckily havent run into too many air bubbles, but the two that i did i sanded out and filled.

Rayra, the total height at its highest point is only 8 inches and then tapers to 6 at the back. I wanted to keep it as low as possible to still be able to urban camp in parking garages, or to leave my vehicle safely in cities.. In terms of glassing in reinforcing metal for my lifts the answer is yes. Right now the best idea I had was to have a friend weld bolts through some metal stock, maybe 2 inches wide 1/4 in thick and a foot or 2 long (still need hinge dimensions) and then glassing those in to bolt onto. Could even use angle iron and butt against roof for more support. But if someone has a better suggestion I'm listening.

Right now I am trying to make sure my hinges have a stopper on them and that the hinge mounts are butted up again my roof rack mounts so that there is one continuous load going from my roof racks down the sidewalls of the topper to my roof. That way I can feel better about loading my roof racks and hitting the trails. One idea I had was to run wood stringers (maybe 1x4 or 1x2) across the roof widthwise at every roof rack bolt point. Then butt my angle iron with bolts welded into it right against the wood. Could even cut/sand a nice fit for them. The wood would help me get a nice fit for the angle iron due to the rounded corners of my fiberglass roof. Drew a crude diagram:

Just one way of Im sure many I could make this work. Other ideas welcome.

Currently working on popping out the shell from the mold with my friend Miniorf who just drove from Cape Cod. Hes got a killer custom Tacoma Pop up. His idea was to cut out a square in my mold and use a metal ruler, then an angle to pry the glass off the mold at all points it would reach.. a very advanced method. But it worked we got the back loosened just need to work the front now.

 

[jscusmcvet]

So cool. Cutting that hole in the mold would have made me even more gray.

 

[rayra]

Next time you want to pop something out of mold / off a buck, give compressed air a try. A small hole in the middle of the pattern, a rubber tip nozzle and low pressure, with the whole thing oriented so the lighter portion is 'UP' - be it the mold or the glass. And it should have separated enough to prize it off.

Since you were destroying your mold to remove it, I would have suggested cutting the corners and any interior bracing and then folding the sides down into the mold, free of the fiberglass. But whatever way works. It's a true test of whether you used enough release or not.


eta

if you have the interior room, would it be any better to glass in something like 1" square tubing, rather than flat stock, or will it be rigid enough fore to aft using just flat stock?

 

[boll_rig]

jscusmcvet, it was a little nerve racking thats for sure. I used the circular saw to get most of the way then scored through with a blade. Didnt do any damage to the shell though.

Rayra youre absolutely right. could have done it a much cleaner way and wish I had an air compressor. The idea was that I wasnt totally ruining the mold. If something crazy were to happen, Like I run into a tree and totally ruin the shell, i could at least put new top sheets on the mold, glass it and use that as my top.

But we were able to pop it off! Took some interesting prying techniques but it worked and looks great.

And here it is on the roof, still a nice fit.. and of course youll see the much nicer pop top in the back there belonging to miniorf







And as for your question Rayra I think it might be stronger if I used square stock. Right now Im thinking of using half round foam rods, maybe half in in diameter and laying those in and then putting down some more glass on the inside. After that I can get a feel for how strong it will be and determine whether to use the wood or some square stock.

Its a little tricky trying to figure out how to glass in the rods as the shell changes shape so much when laying on its back. The only thing im thinking is hanging it from the corners to put them in, that way the roof keeps it convex shape. Anyone got a better idea?