Hi Folks,

An expert modeler once told me that I should seal any spackled areas with CA glue 'before' glassing over them. This technique will prevent the fibreglass (once dried) from peeling away from the wing/fuse as time goes on. The tricky part in this process is that if not done carefully, the fumes from the CA glue can sometimes melt the foam just beneath the balsa sheeting. My question is, how many of you out there use this technique and have you come up with any differing techniques that also work well? Thanks for any input.

Steve

I make cowls using styrofoam plugs. Generally I put on about 3 layers of 4 or 6 oz open weave glass. Between layers 2 and 3, I fill in any voids with spackling and do a finish sanding job. Then do layer 3. I have never sealed the spackling with anything. Have'nt had any problems yet. I will be doing a complete glass job pretty soon on a wing mfg P-38 and will use spackling to do the finish sanding job like I always do. The important thing to remember about spackling is to sand 99% of it off. I slop it on liberally but sand most of it off. I dont do fillits with it. I used spackling once with ca as a fillit and found that it was brittle around a squared edge. Was used to fair a wing LE into the fuse on a P-51. The cracking was not a disaster, just a little bit. Just made me mad after all that work to make it perfect. Still havent done a perfect plane <g>. Just my experience with it.
Edwin

I use lightweight fillers of various kinds in the early stages of plug making, including lightweight spackle. Once the first layer of glass goes on, I stop using those "soft" fillers, and go to either acrylic auto body putty, or epoxy and microballoons. (or epoxy and talc) I've never had the glass separate from the underlying spackle either, and some of my plugs are 10 years old. (I believe that the epoxy would harden the spackle as well as CA, but be easier to sand.)

This is probably just a "quirk" of the particular chemicals your friend used, but I don't think it's a common problem.

The CA will prevent the resin from adhering, I have never had resin lift from a spackled area.

Vince