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Fiberglass tips or tricks

6PKRTSE

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Working with fiberglass hood and scoop for the first time. I am going to need to do alot of cutting and splicing on each. Any tips or tricks when working with fiberglass? Can I just use cardboard or template hard board for a backing until I can flip over and do the other side with resin and more layers of mat?
 
I am not a body man by any means, but I have done a fair amount of glass work on my vintage ski doos.
It is fairly easy.
I use tinfoil tape for making different shapes and as a backer.
 
Okay, thanks for the replies. I am doing this myself. I will give the tin foil tape a try. May start on it next weekend.
 
I should’ve been more clear in my last comment that I made. Didn’t mean to sound rude or anything. I made a 34 Ford sedan out of fiberglass 25 years ago. Used a respirator, coveralls, gloves and everything. I was pulling fiberglass from every crevice of my body, some places I don’t even want to mention. Wished that I’ve taken pictures of the mold and I made it from.

Post pictures of the steps that you take, that would be pretty cool to see.
 
Had to fix a Fiberglas hood that the owner forgot to put the pins in and it flew off. The scoop was almost ripped off and the front 1/4 of the hood was like a hinge, it was cracked all the way across. I used aluminum window screen and SMC glue. The hood flew off not once but twice after I fixed it (Maybe it’s time to go back to hinges?) Still holding together.

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It's not bad other than the sanding which can be really bad, minimize your sanding with clean work and suit up. A great way to minimize sanding and help you get a better surface is by using plastic but don't use thin plastic (Can be hard to remove). Once you've made your repair lay the plastic over it, with the plastic in place you can smooth it out with your bare hands and get a nice flat surface. You'll also find the oriented mat a lot easier to work with vs the woven cloth around contours, the woven cloth likes to bubble and create pockets.

When repairng cracks V out the area to build a full thickness repair, thoroughly prep all repair areas with coarse sandpaper and pre cut your fiberglass before you start and you should do fine. I also keep a qt of fiberglass body filler laying around, it's virtually the same thing but is handy for adding a bit of material to low spots.
 
To minimize the itching, cover yourself in baby powder.
The best way to get fiberglass off of you is to not get it on you.
The talcum powder will keep the dust out of your pores.

Contact USComposites in Florida. Look up the website.
Don't buy the resin and glass from a home improvement store. Use good vinylester resin (VE700) not the polyester garbage from Home Depot. Much better strength and working time is better.

Use bi axial sewn fabric (woven cloth with a mat backer sewn to it) as opposed to chopped strand mat. Much, much stronger and easier to work with. Chop mat is heavy and much weaker than sewn fabric.

Uscomposites sells a release agent for use with whatever you use for a mold.

Also, I wear a tyvec suit and rubber gloves. Tape the gloves to the sleeves of the suit. Again, way better to keep the dust off of yourself than to deal with 3 days of itching.
 
The company that makes the hood and scoop sent me their products to do the repairs so I have the same mat they used when they made them original. Thanks all for the tips.
 
All good tips. If you're really new to this there are good tutorials on youtube. One of the most important things that beginners do wrong is to overload the resin. You want as little resin as possible to saturate the glass matting and still have no air bubbles. Too much resin adds no strength and makes the product more brittle. Use an air roller (should be available where you buy your supplies, also on amazon) to press the glass cloth and matting together and squeeze out excess resin.
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Not knowing exactly what you’re doing it’s a little difficult to direct you. If you’re cutting and stretching things. Wooden buck/mold is best. If you’re making a one off piece. Foam mold to glass over works best. Any time making repairs or reworking glass. Fiberglass mat is best. Any cuts or sections feather them and build from center out with mat and resin. For quick drying resin I use SMC resin. Sets up in minutes and is more stable then fiberglass resin. When you get to your finishing stages evercoat 4+1 primer hands down best polyester primer for fiberglass.
 
Not knowing exactly what you’re doing it’s a little difficult to direct you. If you’re cutting and stretching things. Wooden buck/mold is best. If you’re making a one off piece. Foam mold to glass over works best. Any time making repairs or reworking glass. Fiberglass mat is best. Any cuts or sections feather them and build from center out with mat and resin. For quick drying resin I use SMC resin. Sets up in minutes and is more stable then fiberglass resin. When you get to your finishing stages evercoat 4+1 primer hands down best polyester primer for fiberglass.

I am cutting a stretching the adapter ring, making a drop base plate a larger/taller scoop to adapt repro shaker parts to fit my tunnel ram and dual Dominator carbs on my Challenger.

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No turning back now. May be more of a race car but still a street car so keeping a somewhat stock appearing theme. Lol.

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A wooden buck is the trick for the scoop. Cheap plywood cut to fit the existing scoop. Cut scoop and and add filler blocks to buck. Fill in the gaps between the pieces with resin and mat. The base would be easiest with foam. Cut trim shape to your needs then glass over it making a new part
 
I had to fill a GIANT 24" SQUARE HOLE in my fiberglass hood. The previous owner of the car cut that giant hole for the hood scoop...way too big.
I used a sheet of aluminum from Tru-Value hardware store for my backing. Coated it with CARNUBA car wax and started my build up on that.
When I had enuf layers to get the thickness I wanted I then flipped it over and the finished fiberglass just lifted right off the sheet of aluminum.
I then cut the hole in a much smaller square size that I wanted.

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I had to fill a GIANT 24" SQUARE HOLE in my fiberglass hood. The previous owner of the car cut that giant hole for the hood scoop...way too big.
I used a sheet of aluminum from Tru-Value hardware store for my backing. Coated it with CARNUBA car wax and started my build up on that.
When I had enuf layers to get the thickness I wanted I then flipped it over and the finished fiberglass just lifted right off the sheet of aluminum.
I then cut the hole in a much smaller square size that I wanted.

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Looks good. Nice job.
 
I know, I know, I am taking too long. Believe me, I wish I had more time & money. Finally got out into the garage a little . Got the scoop, hood and base stretched 3" & fitted all around everything to fit the dual dominators on a tunnel ram, sits nice. Even will still be able to use the seal to seal it all of to the hood. Marked the scoop as it sits now to know how much of it stick thru as it is. Going to fiberglass it all back together & then stretch the height next.

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Here's the one I made from scratch using a wooden form and oriented mat. One poster says use woven because it's stronger...... yes it is but your not building an airplane either! I only suggest the mat because it's much friendlier to work with in contours and waaaaay strong enough for a scoop.. they make boats out of the stuff!

I'd remove those riveted brackets, mount the scoop to something flat, prep the outside, prop up any sag, tape off the inside gap and glass the gap shut. I'd sand a long bevel to a thin edge allowing the repair to overlap a couple inches on each side then start off with mat wide enough to fill the gap progressively making the strips wider to fill the bevel until you've built the thickness slightly above the original surface. You should have no trouble pulling this off easily with great results. :thumbsup:
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Thanks for the tips. Yes, I will be removing the brackets eventually. I am just using them for all of the mock up stages for now to make sure everything works , lines up & how it looks more than anything.
 
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