LargeScale88

Hello Everyone...I am just finishing up the sheeting on my P-51, and am getting ready to fill the dents and what not in the wood. The filler I always used is gone, I can't find it anymore. I have used Bondo (on fiberglass), and have found Bondo Ultimate, but I'm not sure if the fiberglass with cure sitting on top of it.

Anyone know of the best filler on balsa that will allow the polyester resin to cure on it?

Thanks

Jason

sensei

Go to Home Depot and get a tub of the light weight wall joint filler, you will love it on balsa under covering or resin and glass. Just place the filler on, allow to sit over night and sand. It sand as easy as the balsa, and is very light...

Bob

speedracerntrixie

My Feedback: (29)

I use this as well. I even go as far as to sculpt wing fillets on my racing models with the stuff and then glass over them. Works great. The only word of caution I can add is make sure your glassing system is epoxy. You mentioned Bondo earlier which is a polyerster base. I doubt polyerster resin and this lightweight fillers are compatable. Never mix epoxy and polerester products as well

LargeScale88

So I can't use the Drywall Mud from home depot with polyester resin?

Thanks

Jason

Gray Beard

My Feedback: (-1)

The tub the light weight filler comes in weighs more then the filler.When in doubt run tests on scrap. I use the light weight filler, I thin it with water for better bonding, let stand over night then sand and glass. So far I haven't had any problems with it no mater what I use to glass with.
Dry wall mud?? I have never tried it.

Tired Old Man

My Feedback: (1)

The light weight filler referred to in the posts above is taping mud. Taping mud has several compounds. All purpose, topping, and lightweight topping. They are all called mud by those in the trade.

Under glass using resin works fine. Allow a couple dsays for all the moisture to evaporate before glassing. Do not use dope over taping mud/light weight filler. Dope will blister.

saramos

Be sure to get the lightweight type. When you pick up the tub, you will notice it to be significantly lighter than other compounds.
If you are filling in after applying glass, you can mix microballoons in with the resin to make a lightweight filler too.

Gray Beard

My Feedback: (-1)

I was just out in my shop looking for something and picked up my filler. Smart & Final light weight Spackle. Good stuff, light weight and you can thin with water to smooth out low areas that aren't very low. I buy it at Lowe's. If I have an open area that requires filling I squish it in , let it dry, sand then use thin CA and it hardens better then using a balsa fill.If there is a gap in a wing saddle I can cover the wing with plastic wrap, lay a bead of this stuff on the water dampened wing saddle, install the wing then the next day remove the wing. Use CA after a light sanding and the gap is gone. Really good stuff.

LargeScale88

Thanks for all the options guys. Time to buy and test out the different products with polyester resin!

Thanks again

Jason

proptop

My Feedback: (8)

Virtually all of the "Bondo" type products are Polyester based, and the liquid Polyester resin / glass cloth can be used directly over cured Bondo.

There is a light wt. version of Bondo if you require more strength than the light wt. spackle. (check out the 3M Bondo Mar-hyde product line )
http://3mcollision.com/products/fill...-glaze/fillers

You can also check out the Evercoat line of products...there's lots of different consistencies (and weights ) of Polyester fillers.
http://evercoat.com/products.aspx