I have a fiber glass 23 t body that I need to glass in the floor and wood supports. I have an article that was in the Sept '96 issue of Street Rodder that explains how to do it. It talks about bonding resin and finishing resin. I checked out the resins at the local NAPA dealer and could not find anything that told me whether it was bonding or finishing resin. Will the NAPA resins work okay, or are they just for repairing damaged fiber glass. I know a lot of you don't think highly of fiber glass, but when you are on a limited budget, you do what you have to.
My limited understanding is finishing resin has a parafin in it to make a hard surface. Bonding resin does not have this. You don't get a hard cure at the surface which remains very slightly tacky so that layers put on AFTER the resin cures adhere better. If you use finishing resin all you need to do is scuff up the top layer and and add your extra layers. I used Duraglas to glue the wood in and then a couple of layers of glass mat/resin to hold it there. Bill
Hey, A "bonding resin'' is used for layup and additional coats and layers of glassfibre cloth or mat, and remains somewhat "tacky" so these additional layers of material will "bond'' together. The "finishing resin" is for fiinish coats, over the mat or cloth, and will actually harden so that it may be sanded and painted over. Doubtful, that NAPA's resin is a bonding type. I'd shop at a paint/plastics outlet. " Humpty Dumpty was pushed "
My understanding from the article was as you said, LongT. The bonding resin does not completely harden. If I under stand what you are saying, I can scuff up the glass resin if it has completely hardened. That is what the article says to do to the body before applying any resin. Can I ad a second coat to the first before it has fully cured?
pimpin paint, I was hoping not to have to do the two different resins, but I also want to do it right so will be seeing where I and get both. Thanks for responding guy's.
When it came time to make my floor & trans tunnel in my TrackT, I checked all the local places(NAPA,WestMarine,PPG,etc) I found they knew very little about "fiberglas" ,especially the different types of resin,mats,fabrics.Most of it was greatly over-priced and the employees knew nothing about methods. I was fortunate to find a local business that makes fiberglas restaurant seating,lift-truck buckets out ,etc. I went to the owner,showed him my project.He was kind enough to give me a crash-course in the basics. He also sold me the material,resins,mold-release,mats&fabrics out of his stock..Not cheap ,but cheaper than the parts houses. I also was able to call him and find ot what I was doing wrong..Check around for these type of companies in your area.
it's amazing how many counter guys (wherever they work) don't know the backside of their supposed specialty; i.e. "how things WORK"..... it isn't too amazing though, to find that a specialist was not only willing to share his knowledge but cut you in on his deals. real PRO's do this often....
www.fiberglast.com buy from them, learn from them. I know composites pretty well, email me if you need advice. i even have fiberglass material i could sell you.
Great info ... I was not aware that there were such things as bonding and finishing resins. Makes total sense. Good to know, I have a fiberglass project in the "thinking about it" stage right now and this is good info. I have "tinkered" with fiberglass in the past (small projects) and always wondered how someone could lay up enough fiberglass for a fender before the resin hardened. Obviously the stuff I have used has been "finishing" product (which has actually been fine for what I was using it for). Thanks for the info
You may also check out companies like www.aircraftspruce.com. They sell epoxy resins and fiberglass. They also have some literature for sale.
Fiberglast.com is a great site, they even have a bunch of tutorials on doing composite work. I think you'll find very detailed answers to your questions there. Buy the bonding resin, if you have a choice. You can buy the parrafin additive if you want to turn it into a finishing resin, instead of buying both. For more strength, check out the iso and epoxy resins, instead of the auto parts store poly's.
auto part store resins are junk....if you can find a boat manufacture then your in business....its cheaper in price due to them buying it in 55 gal drums, it sets up better, and higher quality. i scratch build my own bodies out of fiberglass using marine grade general purpose...works amazing.
kingpins has got it. West System resins, available at West Marine, are the best. You'll need some 105 resin, hardner and some glass mat & glass cloth. Get some measuring cups while you're there. This stuff works GREAT when mixed correctly. It's probably a little more expensive than what you'll find at an auto parts store, but it really works well. Here's a link http://www.westsystem.com/ss/105-epoxy-resin/
Thanks for the links guys. I will be checking them out. One concern I have with a the bonding resin is that if it always stays tacky, doesn't that take away from the strength of it, even if you put a finishing resin over it?
Just a note here: If you happen to use any metal (steel, aluminum) as backing or bracing, rough it up before getting ready to glass to it; before applying resin, give it a thin coat of bondo. Then 'glass to the bondo. Fiberglass resin will seem to stick to the metal, but will get brittle at the joint later! Great points hammered into me by Dick Williams, owner/operator of Poly Form.
the only way you can weaken fiber glass is to over use resin per your cloth. to answer your question as long as you use a correct amount of resin/hardener on your cloth no matter if its bonding or finishing resin it will be super strong DO NOT OVER USE THE RESIN. you can control drying times by your hardener. ive seen alot of guys make the mistake of doing all the procedures correct and then finishing the final layer off with tons of resin....BIG MISTAKE!!!! it wil crack like a egg shell. your strength is the cloth you use....not the resin....thats why for building i use burlap and finishing i use fiber glass cloth or sweatshirt material. take time and make sample patches before you dive in and create a mess...
Wow!! after checking out the above links I have decided to abandon the fiberglass body and find a steel one. Just kidding. A lot of good info on those sites. I actually have and old Aircraft Spruce catalog around somewhere, was going to build and airplane at one time. The West System products seem easy enough to use and there is a dealer near by, so will probably go that route. Again thanks for all the info.
What "kinpins" mentioned is good advice. The NAPA resin will work just fine. Just use the amount of hardner per instructions on the product. Too much resin will weaken the strength of the fiberglass mat. Do thin coats and work out all the air bubbles. Let it harden, ruff up the surface and apply another layer of mat and thin coat of resin again if you feel you need more strength. Epoxy resins are very good but can be high dollar. And with all resins if you don't use them up in a short amount of time they will begin to harden in the can. The good old polyester resin ( The Napa stuff) is fine for what you are doing, and its available in small cans. If you want to make it all smooth and purde, ruff it up again and go over the area with some body filler and prep for paint. Body filler is basically polyester resin and fumed silica. Wear some plastic gloves. This stuff can get messy. Clean up with Acetone. Its also a good idea to protect your lungs with a good carbon filter mask. After working with this stuff for too many years, I found out the hard way. Its not good to inhale the fumes. I remember many burned-out surfboard builders back in So Cal. Have fun Kramer, be safe.
visor, as you mentioned the NAPA stuff is less expensive, and the epoxy does seem to run more than I wanted to spend. I sort of know about the fumes. I repaired a crack in my hot tub a few years ago. Even being out doors with plenty of ventilation that stuff was nasty. As it will be a few weeks before I am ready to fiber glass, I will continue to research what is best to use. Thanks.
Your cloth to resin ratio should be as close to 60:40 by weight as possible for best strength. Also remember poly resin will not stick to epoxy, but epoxy will stick to poly. You should try to find out what kind of resin you are bonding to.
scummy13, thanks for letting me know about the poly not sticking to the epoxy resin. I called speedway, as I have a speedway body, and they could not tell me which resin was used. However the guy I talked to said that if I used an SMC resin I would have no problems. But through some searching it seems to be more of a process than a resin type. Think I will just go with an epoxy type and be done with it.
Having worked in a fiberglass shop there is some good information here. Matting is definitely the way to go for rigidity. I have also done layups with mylar casing using vacuum. Get all the air out of it and don't forget to buy lots of acetone.
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