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RROLDSX Randy R
Delta, BC, Canada   CAN
I'm still envisioning my Cyclekart build and decision on the inspiration car and skill level considerations. I have had a thought on body works. I do not have an English wheel nor the skills to use one. I wonder if anyone used wood or foam shaping with a shrink wrapped finish. I plan on researching further to determine if thicker media is possible to give the finish some strength. If that is not feasible, I wonder if it can be of use as a release finish for the dreaded fibreglass application.

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Smoky Avatar
Smoky Silver Member Don Schmok
Salmon Arm, BC, Canada   CAN
Don't know about shrink wrapping, but lots of builders use FG over wood. You can get some very nice shapes with this method. Adding carved foam and glassing over it can make some tight corners.

My body is all wood, and simple shapes, I used FG over my engine cover. It was the first time I had tackled such a project, could sure do a better job next time.

But my kart is strong, and the body survived the Orchard race in Tieton, and they tell me that is the acid test.

Now to get some more power!



1929 Riley Bitsa

CmdBentaxle Avatar
CmdBentaxle Dave D
Federal Way, WA, USA   USA
1950 CycleKart Italian "1950 Ferrari 166 F2"
I'm not aware of a shrink wrap finish process, but I vinyl wrap vehicles (among other things) for a living.
All the complex bodywork on my car is built up balsa strips over wood frame and sculpted foam then glassed over with 4oz cloth and epoxy resin. I wrapped the entire car in vinyl. It is light and quite resilient.

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RROLDSX Randy R
Delta, BC, Canada   CAN
Thanks fellas, I guess there's no avoiding fibreglass. Just as well, I think it's the way to go anyway.

Randy

geezerduck Avatar
geezerduck Tom Petry
Montclair, CA, USA   USA
Why not cover the framework with Fabric like they do on vintage wood and tube frame aircraft. As a retired aircraft mechanic who specialized in vintage and antique aircraft restoration it's fun to work with and light weight.



Life is good on the lunatic fringe, Tom

Woodysrods Silver Member Brian Woods
Westbank B.C., Canada   CAN
I was at a aircraft repair and restoration shop and saw this fabric.........it is strong too!thumbs upthumbs up
Woody

geezerduck Avatar
geezerduck Tom Petry
Montclair, CA, USA   USA
It has a history in vintage cars too. The Nethercutt Museum http://www.nethercuttcollection.org/ has a beautiful small Bugatti coupe with a fabric covered body.



Life is good on the lunatic fringe, Tom

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greggkishline Gregg Kishline
Kenosha, WI, USA   USA
Many new users are intimidated by fiberglass. Not to worry. It's messy and stinky, but you can get nice results which are quite repairable. If this is the wrong place for this discussion, somebody move it.

If you're considering a wet lay-up for a body-build (or parts), I have suggestions. I'm defining 'wet lay-up' as the process of creating a rough-finish fiberglass body (whole or parts), using a body buck shaped like the finished part. No mold is made or used.

Years back, I wasted 6 weeks making a mold for a single part. The mold came off a hand-made, primered buck (it was a compound shaped tail, in scale). When I was done, I realized I could have skipped the mold step entirely, in trade for some surface/finish work on the resulting part. Six weeks vs a few hrs of finish work - it was a no-brainer, next time around. Most of the one-off bodies I have made since are wet fiberglass lay-ups done on a body mock-up. When you need multiple copies of bodies (or parts thereof), make a mold. For one part, to hell with the mold. My experience, my opinion.

It's less intimidating than it sounds, believe me.

Many other guys have their own solutions to getting a surface that holds up, under application of wet polyester resin and hardener. Most foams dissolve when they come in contact with wet resin. Some don't. You better know, before you mix resin to make your part. If you use bondo to create the surface of your buck, it's much less of a problem but it's still a problem.
What to do? Put a barrier coat between the buck and the resin/cloth. That barrier can be any number of things that isolate the resin from the surface of the buck/mock-up. In varying combinations, I have used: mylar packing tape, aluminum foil, drywall compound, bondo, automotive primer (rattle-can is OK, but some dry way too slowly - test!), and water soluble mold release agent. Drywall compound works as a barrier, but it doesn't feather well, on foam.

Large, compound-curved surfaces on a foam buck are problematic. If your bondo-working skills are lacking, the mock-up of a large compound area is easily shaped in foam. A plywood bulkhead is a real aid in maintaining symmetry ( ....or MDF or particle board, or .... Avoid chipboard, spend a buck).

I built a body that was 100% compound curves and used the following approach to speed things along: I wrapped the foam buck with aluminum foil, attaching the edges of each section of foil with mylar packing tape and rolling down the wrinkles. Avoid denting the foam when pressing out the wrinkles. The goal is to get a tight wrap on the foam, avoiding air gaps.

(An adhesive vinyl wrap might work, if it's stretch-able and resists wet resin - certainly worth a look.) It bears repeating, compound surfaces are the most difficult to lay-up and to remove.

Ideally, a fully-primered and sanded surface (#180, at least) will release the part, if release agent is liberally applied beforehand. But foil works, altho it usually comes off with the part.

After foil, I wet-coated the foiled & taped surface with release agent, which dries quickly. Then I draped fiberglass matting (I used random, not woven matting) to cover the foiled surface. I prefer ripping the matting apart because the edges blend un-noticeably when they're painted with wet resin, and torn pieces fit on compound surfaces very well. Big pieces of matting don't lay down very well on compound surfaces.

Over tight curves, or in tight reverses, I de-laminate the matting and apply it in thinner layers, to conform better. I typically apply three full layers of matting for a body, but that depends on how thick the matting is, to begin with. The thickness of the resulting part should be enough to prevent oil-canning, when you press it.

If it needs more thickness after coming off the buck, more fiberglass matting/cloth/resin can be added on the inside, for strength.

Carry the fiberglass over the edge of the part, extending it. Makes removal easier. Trim the edges when fitting the part to the car. 4" cut-off wheel works slick on a drymark line.

Patience is your friend when removing the new part off the buck. I have been known to put an air fitting in the wet glass so I can blow a large part off. Hint: pack the air outlet with a little car-wax, to assure that compressed air travels between the buck and the new part. I like using water-soluble release agent (on the buck), because you can force water into the air fitting, when removal gets difficult. The water eventually dissolves the barrier between the buck and the part, making release of the part progressively easier. Remember what I said about patience at this point. Once it took me two days to get the top half of a body off in one piece.

Incidentally, bodies can be laid up in several different steps, doing one area at a time. Peel the first area loose before laying up the next area, making the final release easier. If the initial section has set up, be sure to scuff the area of overlap when adding new material onto a wet lay-up that has set up.

When the parts have been removed from the buck, make your 'finishing' life easier. After scuffing the entire exterior surface (#40 or #80 grit), add a layer of wet resin to the whole thing - dripping wet. This layer acts much like a gelcoat layer on a professionally-made part. It locks down the hairs that would otherwise stick up during finishing. And this added coat makes for less finish work.

After the wet-coat has set up (like the next day), hit the whole exterior again with #40 or #80 on a DA, focusing on the high spots. Leave as much of the final coat as you can, and still try to level the overall surface. I prefer to finish off the exterior with a polyester glaze (hardener required for setup) - chemically this stuff is the same as the resin used to make the part. (By the way, the bodyshop supply stores will sell you a gallon of Evercoat resin, but it's typically a double-sawbuck more than WalMart, which was not quite $40 for my last purchase.

Strong suggestion for sanding: Work in an area where you can blow ALL the particulate away from you - and use a good particle mask. I'm 72 - - - Trust me. I use one window fan and two squirrel-cage fans, right next to the sanding operation. This particulate garbage should NOT enter your lungs - none at all. Am I clear???

For tight, small structures like the lip of a grill opening or sharp changes of direction, it may be easier use 'butter' or to make them separately after the body's removal from the buck. Quarter-panel scoops fall in this category - make them separately on the buck, remove them, and laminate them onto the body before final surfacing begins.

Making/using BUTTER: Scissors-cut some fiberglass matting or cloth to make a loose pile equivalent to a golf ball. Hell, make two. Your target fiber is maybe 5/16" long. Take a common 6 oz. plastic yogurt container, and fill it half-full of resin (no hardener yet). Add the chopped fiber until you get a consistency that will hold its shape when you trowel and spread it, while making the desired shape. If it sags or flows, add more fiber. Play with the ratio of resin to chopped fiber. When you're happy with it, add 6-8 drops of hardener and stir thoroughly - like for a minute - cleaning the edges constantly. Popsicle sticks (shaped like a screwdriver tip) work good at this point. Feel free to use masking tape to hold butter where you want it - the tapes comes off easily after hardening begins. Remember to scuff all surfaces where you want new resin to stick.

[ The yogurt container is food grade plastic, and it will not dissolve in contact with activated resin. And the buildup of leftover hardened resin pops out with a good smack, when it's inverted. These can be re-used many times,including wash-thinner use. ]

Better have a gallon of automotive wash thinner on hand to clean tools, hands, etc. A box of disposable nitrile or latex gloves is recommended for the new user. Again .... Either work in an exhaust-fanned area, or work with the garage door open. The fumes are nasty and dangerous. Fiberglass dust is even moreso. I like small disposable paint brushes for resin application (Menards, Home Depot, etc.), but I rinse them with each use in a thinner can and get many uses for each one.

P.S. a piece of stainless about 1/2" x 15" x .050" makes a slick tool for de-laminating parts, starting at all the edges, inserting it between the new skin and the buck.

P.S.2: I prefer to remove new parts within an hour or so, before they are fully set up, because they flex more - again, to facilitate removal. Next day, these parts will be pretty stiff. Release is visible from the outside, as the part separates from the surface of the buck. During removal, if you see stress-induced marks indicating fracture or de-lamination within the new part, you're flexing the part too far - back off and take a different tack, for removal. The internal de-lamination will appear as lines of striation, where the greatest stress occurs. Avoid this.

P.S.3 - When applying resin, use a stippling technique to work air bubbles out of the glass fiber. If the resin is still wet, you can poke any big bubbles with an awl and squeeze the bubble out. They make rollers for this, but you're always cleaning them with thinner. It's the builder's choice.

This was supposed to be a few short hints - but I see I went nuts, probably because I remember how much waste and failure I went thru, to finally get good results. I have lots of photos of these processes and failures, having built many cars and parts from scratch. I've attached pictures of one car, showing the egg-crate&foam body buck, the foil barrier, the wet lay-up body (removed in two halves and then laminated into one piece), the follow-up wet coat on the exterior surface, and the finished product - no flat planes on the body, whatsoever - all compound curves..

New users of fiberglass need not freak out - you can get any damned shape you want with a wet layup - without a mold - especially if it's just one piece.


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body halves - removal of the bottom half, 11-7-11 cropped, lightened.jpg    42.3 KB
body halves - removal of the bottom half, 11-7-11 cropped, lightened.jpg

body halves - removal of the top, 11-8-11 lightened, cropped.jpg    40.8 KB
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body halves - laminated, resin-coated 12-16-2001 002.jpg    47.2 KB
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RROLDSX Randy R
Delta, BC, Canada   CAN
Thanks Gregg! That was an excellent write-up. I wonder if this could be a sticky in the Technical Section?

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Edgewater, FL, USA   USA
Wow impressive work. I have seen mylar used then glassed over.and fabric. Both work well.

chrisenamels Avatar
chrisenamels Silver Member Chris Brown
Llangadog, Carmarthenshire, UK   GBR
Good write up Gregg, a couple of comments:

Glazing resin can be made up with one part of laminating resin to 3 or 4 parts gel, if you have both to hand it's cheaper than buying it.

A washer roller will help with the wetting out process, reducing the amount of resin needed, and so the weight. A roller is easily made with a mini paint roller with the roller removed and replaced with alternating small and large washers.

I use strips of 1/16 plywood for removing model boat hulls from moulds, it's a good combination of stiffness and flexibility, and won't scratch the moulding.

Chris

Bow Avatar
Bow Reverend Bow
Yuma, AZ, USA   USA
1929 Morgan 3 Wheeler "BME RIP Special"
In reply to # 25342 by geezerduck Why not cover the framework with Fabric like they do on vintage wood and tube frame aircraft. As a retired aircraft mechanic who specialized in vintage and antique aircraft restoration it's fun to work with and light weight.


Hey now, don't give my secret away!



Bow

Cut it with and Axe, Beat it to Fit, Paint it to Match

geezerduck Avatar
geezerduck Tom Petry
Montclair, CA, USA   USA
Just saying...It's easier than fiberglass, you don't end up itchy and it's a lot quieter than beating on aluminum.



Life is good on the lunatic fringe, Tom

Bow Avatar
Bow Reverend Bow
Yuma, AZ, USA   USA
1929 Morgan 3 Wheeler "BME RIP Special"
In reply to # 28410 by geezerduck Just saying...It's easier than fiberglass, you don't end up itchy and it's a lot quieter than beating on aluminum.

Exactly..

I hope to be covering mine tomorrow



Bow

Cut it with and Axe, Beat it to Fit, Paint it to Match

LowellR Silver Member Lowell Roemke
Tempe, AZ, USA   USA
Some pictures I took at Tieton 2015 of fabric covered CycleKart


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