Fiberglass Bodywork Question

[tauruck]

 I'd say 200gr weight should do the trick. If you've made a mold already my only suggestion is to place the fabric in dry and start wetting it from the middle and work outward.
PM me or email and I'll help any way I can.

Ron I found this.
http://www.fibreglast.com/product/Bi_directional_E_Glass_1094/Fiberglass_Fabric?gclid=CjkKEQjw5qmdBRCn--70gPSo074BEiQAJCe7zbc_-eCs70VHd8mQPnHMIAEx2XhUmQULoad6P_RXfZfw_wcB

John is right about twill weave. I called it woven  . They have two types. Get the silicon washed variety. It's better at staying together.
The weft and warp don't separate when handling.
Another cool idea that will save a lot of heartache is to use 3M Spray77 adhesive. Spray some along the line you want to cut.
Give it 5 minutes and then trim. Its like cutting paper and you won't get unraveling at all.
Remember, you don't have to use one single piece when doing the lay up. You can use smaller pieces that overlap until you gain more experience. Also stronger.

[bbarn]

If you haven't picked a mold release agent, PVA works well. It is water soluble and parts pop out of molds without too much trouble. Get a cheap Harbor Freight spray gun and write PVA on the cup and treat it like a primer gun. It is not recommended to spray paints out of the gun after using it for PVA.

Another trick is to use the clear packing tape to cover parts that you don't want to have anything stick to. Epoxy won't stick to it and the tape won't bond to surfaces like duct tape is prone to do over long periods of time. If you use the Mylar tape and plan to bond something else where a part was in contact with the tape (after curing), be sure to rough the surface well before the next bonding. The taped areas will by shiny and smooth.

Rip-stop nylon is a cheaper alternative to peel-ply. If you use it as a top coat, you can squeegee over it without moving the material below it. Excess resin can be drawn up through it to scrape off. Once cured, this layer peals off fairly easily and leaves a nice surface for bonding too (rough but not coarse). Get it in white, it will readily show bubbles in the layer(s) under it that you can work out with the squeegee.

We also did quite a bit of measuring by weight for the resin mixes in the beginning. It is accurate, but so are the pre-set pump dispensers that fit on top of the cans. They let you mix small portions so you don't over do it and make repeated trips to mix additional material without much hassle. You don't have to think much with them either - One pump from "A", One pump from "B" - Lather, rinse, repeat.

Don't be afraid of the epoxy, get a slow or medium hardener so that you have time to work with it. Take your time and work methodically. Get gloves...lots of gloves. Lay a few extra out when you first start (regardless of poly or epoxy) because you won't believe what you forgot to get ready before you mixed your resin. You'll burn lots of gloves up front, but after practice, you can do certain layups without gloves and not make much of a mess at all.

[tauruck]

There's a man that has worked with the "stuff".

Good advice.

Funny, I've never sprayed PVA release agent. I use a sponge but I'm definitely going to spray the next job I do.
Its the only release that works for me.

I tried the Freekote route and I still haven't recovered.

[sofadriver]

I can but I work in metric terms. Comparisons will be the same.
 

Thanks, tauruck.
I've done a lot of repairs but this whole building a body from scratch thing is new to me. For sure, I'm not impressed with the stiffness of poly.

[tauruck]

Keep in touch if you need help. You can email if it's easier. pro1racing@telkomsa.net
There are lots of tweaks you can use to get the stiffness you need.
I'll walk you through the process step by step.

Probably the best move I ever made was using MS primer in place of gel coat.
Polyester gel coat goes on too thick especially for novices. It's prone to cracking. You've seen those star cracks?
Epoxy gel coats are difficult to work. If you use PVA release like I do the gel coat pulls it off the mold. At least that's been my experience.
The MS is cool. You spray it into the mold and when it's cured you just lay up the fabric. On mold release you'll have a primed part ready for paint.
Your painter will love you for it. No sanding of gel coat to get a key and the part will be much lighter.

Mike.

[JimL]

Couple of things I do for epoxy work:
- watch garage sales for old card tables.  Buy every one you can.  Tape wax paper onto them and then lay your dry precut cloth pieces on tables.  Different sizes for different tables, dont stack the parts, so you can pick one up with sticky gloves.  Wax paper keeps the tired old tables from snagging the fiberglass cloth.
- a glass bowl of acetone, for dipping your roller tools and Fisker scissors.  I keep a metal pie tin over it, so I can pick it up, clean a roller, drop the lid (pie tin) back in place.
- a good chem mask.  You dont get to learn ahead of time, but each and every one of us will hit a lifetime limit on exposure.  Youll know when you get there by the duration of the vomiting episodes.  I hit the wall about 10 years ago....only small layups, now.
- I like to start epoxy layups about midnite.  It buys me more work time, so I can slow down and think.  It also means I go straight to bed after cleanup, and can sleep off most of the "spin dizzy" episodes.
- if you need to lay up/fill a small area that has "bad gravity" (an area on the lower side of a part that cant be flipped over), make a large flap of duct tape sections.  Stick the bottom edge of the flap hanging like a dogs tongue on a hot day.  Stick it just below where your layup/fill will occur.  Apply your epoxy materials, and then squeegee the "tongue" upward and smooth out.  Leave the flap on until cured, the epoxy wont stick to the duct tape glue.  I've used this method to fix "blister boats", knocking out a complete hull in two nights, when the yard guys were going to take a week of filling and grinding.
- outside corners can be tough on small areas.  Sometimes I fold a band of wax paper and pull it over the problem corner as a slight tensioner.  Many times , it has enough grip to hold the bend just by the long area of flat contact on each side....weird.  It is easier to sand off a little stuck wax paper, than to grind through the bubbles and make repairs.

Hope this is useful.  I just do amateur stuff, and real low cost, so....not very high tech.
J

[tauruck]

Excellent post Jim.

I hear you on hitting the wall.

[wobblywalrus]

All of my fiberglas work gets saved until it is summer when I can do it outdoors with either a gentle breeze blowing or a fan.

[JimL]

I have forgotten if this link is in an older post, so will add it to this thread.

http://home.modemss.brisnet.org.au/~jmiller/leinfam/repairing_1.html

There might be something useful for making or repairing various bits.

[wobblywalrus]

There are all sorts of possibilities with plastics.  They weld together with a tool that looks like a soldering iron and the use of plastic welding rod.