filling without sanding

[mossieramm]

Hi all, I've got a few wing-to-fuselage joins to fill on my Juggs (Acedemy P-47), and I've tried the CA/accelerant way but haven't had the proper results.

I use the thin CA, drop a droplet in the join and let gravity “pull†the Ca into the join. I then add a drop of accelerant to the CA. But instead of just “drying†the CA, it expanded the CA and spilled over the join. So instead of a nice flush, I have a bulge (must be the Juggs, sorry couldn’t resist) to sand down.

Have I used to much accelerant ?? Or is it something else ??

Thanks,

David.

[jonbryon]

I don't think it's possible to use CA as a filler without having to sand it, whether you use accelerator or not.

In fact, I don't think it's possible to use filler (or Mr Surfacer, or whatever) without sanding *at all*. People say they can do it, but the joint always seems to be visible afterwards if you look closely enough...

Cheers

Jon

[GGoheen]

Agreed, as Jon mentioned, I still think sanding is very much a requirement still when using CA as a filler. About the only technique I've used that seems to keep your sanding to a minimum is when you use regular tube type putty....then wipe it flush with a Q-Tip dipped in nail polish remover (or lacquer thinner, as I prefer). Still, there always seems to be a residual amount that will require a slight bit of sanding.

Regards,

Greg

[MickeyThickey]

Accelerator does that. Likely because it cures from the surface down, rather than the edges in. And because it does so very quickly, the gasses released while the CA cures get trapped, and bulge out.

Simple solution: don't use accelerator. Just apply and let the CA cure on its own. For most smaller gaps, if you're careful, you shouldn't have much excess to clean up. And you're better off using multiple un-accelerated applications - using accelerator can form bubbles/pinholes in the CA which may require further filling anyway.

For the 'without sanding' bit, use CA de-bonder on a Q-tip to clear up any excess glue. THIS is the important part, NOT using accelerator. You're substituting CA for the usual putty, and de-bonder for acetone.

And no, it doesn't completely eliminate sanding. I use the technique frequently (as standard, really), and always brush a coat of Mr. Surfacer over the seam, let that dry, and rub down with wet/dry to completely eliminate it. The Mr. S fills in any small depressions, acts as a primer to see how good the seam actually is, and feathers out well to completely blend in to the surrounding plastic. So it's not NO sanding, it just greatly reduces the amount needed for seamwork.

Edited October 19, 2007 by MickeyThickey

[markiii]

Accelerator does that. Likely because it cures from the surface down, rather than the edges in. And because it does so very quickly, the gasses released while the CA cures get trapped, and bulge out.

Simple solution: don't use accelerator. Just apply and let the CA cure on its own. For most smaller gaps, if you're careful, you shouldn't have much excess to clean up. And you're better off using multiple un-accelerated applications - using accelerator can form bubbles/pinholes in the CA which may require further filling anyway.

For the 'without sanding' bit, use CA de-bonder on a Q-tip to clear up any excess glue. THIS is the important part, NOT using accelerator. You're substituting CA for the usual putty, and de-bonder for acetone.

And no, it doesn't completely eliminate sanding. I use the technique frequently (as standard, really), and always brush a coat of Mr. Surfacer over the seam, let that dry, and rub down with wet/dry to completely eliminate it. The Mr. S fills in any small depressions, acts as a primer to see how good the seam actually is, and feathers out well to completely blend in to the surrounding plastic. So it's not NO sanding, it just greatly reduces the amount needed for seamwork.

That's some excellent tips there. I have to try them.

Mark

[jonbryon]

FWIW, I agree with the above: you can *reduce* the amount of sanding necessary, but not *eliminate* that part of the process (IMO).

Cheers

Jon

[mossieramm]

Thanks for the tips guys. Specially like the debonder tip. I'll definitly be trying that.

:D

David.