1BADHD

I was at our local Wal-Mart last night and seen that BONDO sells both fiberglass and Resin. I was wondering if anyone has ever used it before? Will it work on foam? The fiberglass was a really corse fabric, (real long stands of fiberglass) Will that even work on a boat? I ask this, becasue my "local" hobby shop is about 70 miles away. If I can get this stuff to work, it will save me 50 miles of travel one way.

TERBObob

My Feedback: (21)

No... wrong kind of resin . And just the BONDO itself is VERY heavy ( not the fibreglass one )
May I suggest do as PRO does ... cover her with MONOCOAT for airplanes ?
I personally know nothing about it , but PRO knows all the ins and outs of the stuff and from the looks of his pictures of his boats ... man .... you sure can't beat the finish !

canadianjosh

You should be able to find both fiberglass and resin at a shop other than your LHS. I don't even go to my LHS for resin and cloth because they sell in small quantities and are more expensive. There should be a shop that specializes in paints, plastics, foams, rubbers, cloths, bagging, signs and so on, in your city. They have resin and cloth for much cheaper. If worse comes to worse order online. Wal-Fart and those stores know jack-s**t about fiberglassing. If you have carved a hull out of foam, then i recommend fiberglassing it instead of monkoating ecause the glass adds tremendous stiffness over foam that even 100 layers of monokote couldn;t make. For the foam hull to be stiff all over, you must fiberglass all surfaces. This will create a sandwich if you can imagine that in your head, the thicker the middle layer, be it balsa, foam, honeycomb core, the stiffer the part will be for the same weight cloth.

pro27

I have used the BONDO Brand of polyester resin on some of my non-monokoted wood hulls. It's cheap and easy to work with along with smelling to high heaven. However, you CANNOT use it on most of the foams we use as it melts on contact with the stuff (chemical as well as heat reaction).

For glassing foam hulls, you're better to go the safe and sane route and use an epoxy resin.

As for FG cloth, the stuff from Wally's is extremely heavy (about 14oz cloth). When I glass a hull, I use 6oz cloth on the hull bottom and 3/4 to 1 1/2oz cloth on the rest, depending on what wood materials I used in construction. For foam, I would recommend the 6oz for the bottom and no less than 2oz for the top surfaces. The weave of cloth you get can make a diference also. I generally use what is termed 'S' cloth, highly moldable on curved surfaces.

For sources other than your lhs, check Sig Mfg or CST. They caryy several weigts of good quality cloth.

Anyone for kevlar cloth or CF tissue? ( $$$$$ )

Selph-Inflicted

There are a few ways of using fiberglass on foam. You can wrap the foam with duct tape to seal off the foam or you can smear Elmer's glue on the foam then glass it.

But in reality, your better off using an E-Poxy or Z-Poxy.

TERBObob

My Feedback: (21)

Duh ! ! ! Did ya ever have a case of BRAIN DEAD ? Thats what I must have had when I wrote that ...
Monocoat over foam .... ( DUH ! )
Thanks CANADIANJOSH for making sure that my GOOF up was corrected . ( man , was I stupid then or what ? LOL )

( little of subject and I apologize )
Hey DADADDYRO,
Do you hand flip ( chicken stick ) or electric flip ? Reason I ask , is that your motor mount doesn't appear strong enough for electric . But , that nose nut makes me think you do use electric . ?

Selph-Inflicted

Terbo...I use an electric start. The motor stand is very sturdy. That is one thing I don't skimp on. I don't like the thought of firing one up and having the motor come off the stand. That could have a bad outcome!!

boogerboy

My Feedback: (3)

You can take 30 minute epoxy or 5 minute if your really fast with a playing card or bondo spreader cover your foam hull with a thin coat. Then you can use the chaeper polyester resin on it. I've done this a bunch of times, just be sure to cover it all! Or your new boat will melt! We also have a airboat I covered 8 years ago with balsa usa fabric drap color aircraft film directly over foam. I have to iron it every year to tighten up the lose spots but it's holdin' up great!

pro27

If you plan on using poly or vinyl ester resins over epoxy resins, it would be wise to test the compatability first. Some will cure over the others, but will not attach/bond to it. Some epoxies after curing, develope a waxy surface. If this is not eliminated it acts like a release agent to the poly/vinyl over it. Years ago, I used to mold speed cowls this way. The mold was epoxy anf the shell was poly. It would pop off every time. No need for release agent.

rcairboat78

I often use the Bondo stuff, i get mine at Canadian Tire, but you can probably get it at walmart too.

Marine Epoxy Resin - I did some boats with that with fiberglass cloth right over the foam, it will not melt it. It even says on the can that it is compatible with styrofoam. It is expensive, you get two 473ml cans which you mix 50/50, and it takes a few hours to dry, forgot exactly, havent used it in a few years. And it costs about 40$, canadian cash that is.

General Purpose Resin - Eats foam like there is no tomorrow, just gotta make sure to seal your foam, balsa is probably the best. But within a week i will test out another cheaper alternative. I will either have a fibeglassed hull or a blob of melted foam

1BADHD

OK, I have went to Home Dept, Lowes and lumber yard and the local hobby shop to no avail. No one carries the epoxy.....I guess I will just have to order ti from Tower Hobbies. Having fun shouldnt be this much work!![X(]

pro27

Not everyone stocks the stuff we need when we need it. I think we can all attest to that.

Most places, including your lhs, will stock the normal sizes and cures for what they sell the most. Trying to find a long cure epoxy like 1 hr or 2 hr is hard today. It's not that it's not available, it is and in large amounts, but most won't stock it unless they know they'll sell alot.

Been there myself. If it were'nt so expensive, I'd be buying it by the gallon.

canadianjosh

Yes you can use a layer of epoxy to initially seal the hull. But i can't remember which way it goes, one will chemically bond to the other but not the other way around. So if you do this the best bet would be to let the epoxy fully cure for 24 hrs, then give it another day, because epoxy continues to harden for up to a week. Then sand the surface with 150 and then 220, to roughen it up. Then put down the polyester resin. The is no use in spending the extra money for vinylester resin, as it does essentially the same thing as polyester, but it is better suited for carbon fiber. You will end up with a mechanical bond between the epoxy and the polyester, which isn't as good as a chemical bond, but will do the job well. SANDING IS CRUCIAL!!!!!, if you don't do it the layers will separate over time. Pro, epoxy resin doesn't have the was in it. These are only polyester and vinylester resins that do, this is because they cannot fully cure in the presence of oxygen. So they add an additive called air-dry, you can buy it and add it to unwaxed resin, that floats to the top and allows a full cure. If you use unwaxed resin no matter how long you wait, it will remain tacky, this is to allow chemical bonds of following layers. As for epoxy, I suggest using West systems 105, or a similar product. www.fiberglast.com has everything you need. Or go to google, and type in fiberglass, you'll get tons of sites that sell resins, cloths, vac-bagging equipment, cleanup, prep, everything needed. Fiberglast.com features a model boater that builds hydro hulls from fiberglass.

ludovic

You might try a marina if you have one close by, or a specialised store for wood workers...I have both in my area and they sell west or east system epoxy, for about$100 can/gallon...verrrry expensive!!!!!![]

dadkins

I have used monkote over foam with reasonable results-Just stay off the grass and pavement.
once it does spring a leak it tends to make a water pocket between the foam and monokote - slowing speeds tremendously. Also your styro has to be CLEAN or freshly sanded for it to stick good.BTW right now I am running straight styrofoam I'll try and post a pic here.
Also - I wanted to comment on what a great website this is> Right on ! keep up the good work.