the family wagon

[family wagon]

Can I bend the PVC foam core with heat? Is there any benefit to doing that instead of cutting, fitting pieces, and sanding off the high spots? I learned from searching elsewhere tonight that BID is short for bi-directional cloth. In step 5 you mentioned both cloth and fiberglass; what's the difference in the two?

 

[taskswap]

"Fiberglass cloth" is sometimes called "cloth" and sometimes "fiberglass" by lazy people like me who prefer single-syllable words.

You can bend the foam core before you do a layup on it. After that, you can park a car on it and it won't bend. Fiberglass is incredibly rigid, especially on a core. There's a story that supposedly the wings of the B-42 bomber (aluminum and steel ribs) droop 1.5 feet at the very wingtips. Remade with fiberglass they'd bend a quarter inch (or something like that).

The standard process is to put the foam where you want it, and shape that with sandpaper, cutting tools - whatever. Get it exactly the shape you want, which is easy (which is why people who like this process... like this process in the first place). Then do the layup, and it keeps that shape forever. You can make curves, angles, join multiple pieces with 5-minute epoxy to make complex shapes, etc. When making things like ducts you can remove the foam core later if you cover it with duct tape before doing the layup - epoxy won't stick to duct tape. For others, you leave the core there and it provides additional rigidity and crush resistance.

You can crumble 3/8" PVC with your bare hands, and shred raw BID cloth the same way. But once laid up (just two layers) and cured, you can walk on both without making a mark. (Lightbulbs going on in my head - I just realized how I want to make my roof deck.) If you make a structural shape like an I-beam and use a few extra layers, you can park a car on it. There's literally a math formula you can use to determine its strength, determined by the type and weight of the cloth you use.

Tools required:
* Epoxy. The $30 West kit from hardware/boat stores is fine if you aren't building an airplane. Get their pumps too, it's like a $12 pair you stick on their cans that dispense pre-measured amounts.
* Rubber squeegees. In a pinch, you can cut one from a coffee can lid - that soft plastic is about the right strength. Round the corners so they don't drag. It needs a smooth edge.
* Mixing sticks and disposable paint brushes. Get the Harbor Freight "chip brushes". Don't even bother trying to clean them.
* BID cloth. You can get all kinds but anything that says "BID" is fine if you aren't building an airplane.
* Disposable scissors. Well, these don't have to be disposable, but fiberglass will dull a cutting edge very quickly. I like the Harbor Freight shears they sell for like $1.99. They last a few months.
* Mixing cups. Wider/flatter are better.
* Microballoons. A 5lb bag will last forever.
* Dedicated hair dryer. Optional but VERY helpful. You want the epoxy to spread smoothly and evenly, and heat helps it along. A heat gun is too much. This also lets you work when it's colder out. You WILL get epoxy on it, so don't use your wife's! Walmart, $10.
* Nitrile gloves. Epoxy is sensitizing! Never touch it. It won't kill you, but you will get a nasty rash, it sucks, and there's no reason to have that happen. If it doesn't happen the first time, it will happen the tenth, or the hundredth - but it will happen eventually, guaranteed. Wear gloves and you'll be fine.
* 3mil plastic. Anything will do, but it's best if it's full width and isn't folded. I buy mine for like $12 a (50yd) roll online from some shipping company. (The folds in the ones from Home Depot make creases in the layup).
* A dremel or (better) Black & Decker rotary tool. Get a few dozen sanding drums and the little raspy cutter thing - the one they sell for drywall.
* Some hacksaw blades. Hacksaw not required. You can make amazingly straight and clean cuts in fiberglass by just hand-pulling one of these blades along a line or straightedge.

Sounds like a big list but a lot of people have most of this stuff lying around. Most of the money goes into cloth and epoxy. For what you're trying to do, with careful shopping, you could probably do it all for $200.

I'm not specifically trying to "pitch" you on doing this project with fiberglass. Plenty of people hate it. But if you DO want to do it, I'll post here all day long about how to get it done. At least I can contribute some value to the forum.

 

[taskswap]

Now that I think about it, I think I'll start a thread just for this.

http://www.skoolie.net/forums/f10/how-to-fiberglass-10837.html

 

[HolyBus]

I believe and trust you but I used to work at a place that sold many new surfboards. We used to make accidental dents with our thumbs when moving them around from display to display or to let a customer have a close look. They were foam core fiberglass skinned boards. Why so fragile? It made me leery of using it where strength was needed.

 

[maggiemae-SKO]

I'm not going to lie, I was a little scared to click that link!



Great article though! I'm glad I clicked it!

 

[bansil]

I'm not going to lie, I was a little scared to click that link!

View attachment 6786

Great article though! I'm glad I clicked it!

................

 

[taskswap]

Hahahaha, I didn't even notice that, it's priceless.

Most surfboards aren't made to be cars. They're made of soft styrofoam, much more like the stuff in your coffee cup or packing peanuts than what you'd find in a boat dock float. They're made with thin fiberglass cloth in only one or two layers because you're only floating a <250lb person, and they're (often) made with polyester resin which is more flexible.

Check out this guy's video. This is cheap-o foam with cheap-o cloth (just loose mat, not long-fiber woven BID) that you'd get at the hardware store. He chats for a long time - jump to like a minute before the end.

I'll post pics of the "real" stuff when I get home tonight - I'm pretty sure I have some scraps lying around. It's only two layers of BID over 3/8" H45 PVC foam. You couldn't dent it with a hammer. You can drive a screw into it, just like wood. But it's definitely NOT soft.

 

[maggiemae-SKO]

Hahahaha, I didn't even notice that, it's priceless.

Most surfboards aren't made to be cars. They're made of soft styrofoam, much more like the stuff in your coffee cup or packing peanuts than what you'd find in a boat dock float. They're made with thin fiberglass cloth in only one or two layers because you're only floating a <250lb person, and they're (often) made with polyester resin which is more flexible.

Check out this guy's video. This is cheap-o foam with cheap-o cloth (just loose mat, not long-fiber woven BID) that you'd get at the hardware store. He chats for a long time - jump to like a minute before the end.

I'll post pics of the "real" stuff when I get home tonight - I'm pretty sure I have some scraps lying around. It's only two layers of BID over 3/8" H45 PVC foam. You couldn't dent it with a hammer. You can drive a screw into it, just like wood. But it's definitely NOT soft.

Yup you are totally right- I've gotten many a pressure dent on my boards. But you look at race cars/performance vehicles- those are pretty solid. Even the thin fiberglass water tank I looked at the other day- pretty solid!

 

[family wagon]

Ugh. Progress in the past month has been absolutely terrible. Been busy doing other things, but most of all held up by that rear fiberglass cap which seemed it might never let go. But.. finally.. IT'S OFF!!

For a long time I avoided cutting the corners, thinking that I preferred to leave that for later after the roof is raised and I see how things fit together. Maybe there would be ideal and/or poor locations for the cut. In desperation I finally gave up that ideal, cut the corners, and then pried the two pieces off separately in relatively short order. It turned out that there was just enough seam sealer left sticking in just enough places that it was near impossible to remove as a single piece.

Normally I'm the kind of person who meticulously cares for tools and avoids abusing them, but this fiberglass removal drove me over the edge. Earlier I mentioned finding that a narrow putty knife/gasket scraper tool worked well when driven in with a hammer to cut through the adhesive. Finally one day, this happened:

Best custom tool I've made in a while. The blade broke at the weld edge repeatedly and it grew 3/8" shorter each time. I went through two scrapers, and probably a dozen welds on each, but it saved a ton of time and effort!

 

[family wagon]

Also finally got the yellow fiberglass insulation remnants cleaned off the ceiling. This deck brush on a 4 ft pole made fairly quick work of it.

The tail end of the bus has turned out not to be built like I had imagined at all.

It makes sense, though: I hadn't noticed it before, but the body is cantilevered over the engine. Now it makes sense why the rear-most window has that giant (wide) channel/post under it, rather than a stub of hat channel like the rest of the windows have. It's the post that carries the weight of the tail of the body down to the floor.

The problem is that I really want to put bunk beds (3 high) over the wheel wells, with a 12-15" high window for each bunk, and there'll be interference between the bottom window and that long horizontal C channel that forms the lower sill of the original window. I'm not sure how to resolve this yet.. Maybe raise that horizontal channel up 6 inches so that it passes above the lowest window? I'd have to extend the post in the middle, but that doesn't seem like any trouble.

 

[nat_ster]

Great pics.

Good to see progress.

Nat

 

[family wagon]

I've been dreadfully.. dreadful about (at least) two things: progress on the bus, and pictures of said lack-of-progress. Having mentioned on a few other threads that I've scraped the tar off the roof of this bus, it's time to post evidence ("pictures or it never happened," blah blah! ).

Here you have one section of the roof after insulation was removed and loose bits brushed away.

Same section, after hot scraping:

This pile of tar junk came from three such roof sections (I think it was just three..):

Finally, most of the process all in one frame:

In text form: I used the 3" metal putty knife shown above, plus the heat gun and buckets of elbow grease, to scrape off as much tar as possible. There's kind of a "sweet spot" with the heat at which the tar becomes soft and scrapes off fairly easily, but then it takes more time to get the next area heated to that point. It took 15-20 minutes per section of roof, except for a session I did in full sun 1-3 pm on a day of above 100 F temperatures. Those sections took "just" 10-15 minutes each. Overall I estimate there were 8-10 hours of work in this step.

After the scraping was all finished I wiped the residue with naphtha. It soiled the rags pretty quickly, and I settled into a two-rag process that worked fairly well. The first rag was soaked with naphtha and was used to wipe down an area. While still wet, the second (less dirty) rag was used to wipe off as much as possible. When the second rag became soiled to the point that it didn't wipe clean very well anymore, the rags were rotated: the first (wet) one was discarded, the second (dry-ish) one became the new wet rag, and a fresh clean rag took on the second-pass role. This step was much faster, probably under 2 hours.

Yet to be done is one more pass with naphtha. In the picture one can see there's still some residue in the top-left corner; I think a second pass like the first should get it pretty clean. Later will come a step of pressure washing (FINALLY!) and maybe de-wax/de-grease prep step before I have foam sprayed on...

I tried MEK, acetone, xylene, and naphtha. All dissolved the tar, but MEK and acetone flash off WAY too fast to be useful. Xylene was kinda OK, but naphtha just worked better. It is commonly found in the paint department at hardware stores and might be labeled "VM&P Naphtha" (varnish makers & painters) or maybe just Naphtha.

 

[Tango-SKO]

Great documentation of a nasty (but mostly necessary) task. Thank you!

 

[maggiemae-SKO]

Seems like so much work to remove that gunk! Yikes!

 

[nat_ster]

Great tech.

Nat

 

[M1031A1]

I'm going through the same process. Lots of work, but well worth it for spray foaming successfully!

 

[family wagon]

Finally, more progress! The raise is so close I can taste it. Or maybe that's the taste of cutting dust..

First, an interesting picture from the tail of the bus. I had not realized before I began tearing the outer skin from the shell that the area covering the engine is cantilevered. It doesn't bear on the bus frame at all. Instead, there's a post and beam arrangement in the wall to hold up the engine compartment and the back end of the roof. It necessitated a change in plans for the raise in that area, but it'll still work out fine I think. This photo shows where I made cuts to leave the post and beam arrangement behind while raising the remainder of the wall. Note the 2x4 tucked under the back end to support it while the roof and walls are away.

Now.. it's time to solicit some advice. First, here's an area where a window is to be deleted. In order to support the sheet metal that will cover this space, and to add additional structure for supporting the roof, I'd like to install new rib material where the green line is drawn. I have sufficient channel material to remove (fully replace) that cripple below the sill. Should I remove the sill and run a "trimmer" or "jack stud" from the floor up to the bottom of the header? I assume removal of the header is a Bad Idea. But what about the sill -- is it important to keep? Does a regular skoolie body, ie one that does not have large windows as mine does, have a sill like this between every rib? I could remove the sill, install the new rib, then make two smaller sills from the one and install them in the gap between the new rib and the existing ribs to either side..

Next question. This one's a bit complicated to explain. The concept here is that the front door is to be deleted, and I'd like to shift the front-most window to occupy the space where the door was. So I'd move the header and sill forward (and the sill upward; the base of the windows is to be a few inches higher from the floor) and will have to make modifications to the rib structure. Effectively I'll be cutting off the factory ribs and un-cutting those that were cut at the factory. The big question is how to make the connection of the new rib to the old where there's very little room to overlap them.

Another question on that one is what about the wheel well? The new rib would be bearing there, and I'm realizing now that doesn't seem like such a good idea. Maybe I have to install a horizontal beam here to carry the load out beyond the ends of the wheel well? I didn't think this window move thing through very well before allowing my heart to get set on it.

One possibility, rather than cutting the rib that has side material and extending the one that doesn't, is that I disassemble this part of the roof too so that I can shuffle the order of the ribs. Let me tell you how much that sounds like fun...

 

[nat_ster]

The wheel well rib is supported at the bottom by the chair rail on most buses.

Also the rub rails spread the load to other ribs with more rivets into the chair rail. They serve as horizontal supports.

Nat

 

[family wagon]

Progress has been slow -- I keep getting drawn into other projects, and the poor bus just sits there neglected. The roof is raised and hat channels halfway secured. Pictures "coming soon."

For now my mind is on getting the new exterior skin sheet metal ordered. The biggest hang-up with that is figuring out the windows. In particular the bunk bed windows are challenging because there are 6 of them. Of course I want them all to match, and don't want to pay $300 each piece...

These bunk windows will be kind of small, maybe 9-12 inches high and around 20 inches wide. It'd be all frame and no glass if they had any kind of slide mechanism for opening, so I'm thinking along the lines of fixed flat glass like that used for automotive rear quarter glass. Hopefully that'll keep the price down too. Having never installed such a window myself I went youtubing and found this remove/install demo. Looks easy enough.

But how to form that inset flange in the sheet metal? Its depth needs to be about the thickness of the glass plus adhesive so that the finished window is roughly flush to the body. I think I could make a template from MDF and hammer form the sheet to form the first bend, going inward. The metal in the corners would have to stretch. But then I have to fold it back into a plane parallel to the rest of the sheet. Hammer form again? Now those newly-stretched corners have to be shrunk so the metal lays flat with no wrinkles. This sounds daunting because I've never formed metal like this before.

Does anybody have any ideas to share for the forming of this lip/flange/whatever-it's-called in steel sheet to accept a quarter window?

 

[sdwarf36]

From windows I've done, the rubber trim has the groove for the glass + the groove for the body right along the middle-you can just put it over the sheetmetal. The window + trim may stick out 1/4"-but thats about it. This is doing standard flat glass on a flat panel-any shape or form in a Land Rover or other cars have that lip formed by a 500 ton press.