Skin smoothing / filling prior to paint

[AviatorJ]

I don't plan on painting the plane myself. However as I'm working though the empennage building there are times a bucking bar slips, or I over drive a rivet creating a less than perfect finish. Was told that this is all fixed prior to painting.

Have been googling around and any talk of filling deals with the fiber glass areas. What is done on the fuselage, wings and empennage prior to painting if anything. Thanks.

 

[MikeyDale]

Everyone uses their favorite filler. I had a few dings here and there and used Epoxy/micro balloon mixture. Sand smooth and no more ding. It is really no big deal. It's one of those things you worry about early that turns out to be nothing in my opinion.

 

[DanH]

I don't plan on painting the plane myself. However as I'm working though the empennage building there are times a bucking bar slips, or I over drive a rivet creating a less than perfect finish. Was told that this is all fixed prior to painting.

Some flaws are ok to fill, while others need correction.

Have you had an experienced builder, or A&P, or technical counselor inspect your empennage? This is the time to correct whatever issues are creating less than satisfactory results.

 

[AviatorJ]

Have you had an experienced builder, or A&P, or technical counselor inspect your empennage? This is the time to correct whatever issues are creating less than satisfactory results.

Have not, will need to find a tech counselor at my next EAA chapter meeting. Here's an example picture... hard to tell on the picture but it's 'pillowy' which I read last night is from not dimpling enough. I used the close quarters dimple set on these so not sure how it wasn't enough.

 

[DanH]

Ok, surely there are some excellent riveters in the Oklahoma City area, so do take advantage of any opportunity to get them hands-on with your project at the empennage stage.

Can't see much in that photo, but no matter. Fill is not acceptable if it covers a rivet head. Filler is for correcting something like a minor smiley adjacent to a rivet, or a panel ding from a dropped bucking bar. The rivets themselves are airworthy or not airworthy, and that includes a hard look at the shop head.

Remember, the best airplanes are often the result of scraped parts.

 

[AviatorJ]

Ok, surely there are some excellent riveters in the Oklahoma City area, so do take advantage of any opportunity to get them hands-on with your project at the empennage stage.

Absolutely plan on having people check out my work. Also I have both some of those smiley faces and at least one dropped bucking bar. As long as it doesn't fly sideways I'm fine with the imperfections... that's what makes it mine.

 

[Kent Ashton]

It looks as if you might be using the next-larger dimple die or going too deep with a countersink cutter. Bit hard to tell from the pic. The correct die on a piece of scrap will put the C/S rivet pretty flat and level.

 

[AviatorJ]

Correct dimple die, I'm very organized with my tools. This is a pic of the nose ribs, I made over dimpled the flange using a pneumatic squeezer. I alway have it pretty tight.. Maybe don't need it that tight.

Anyhow appreciate the help. Going to not worry until I get some experienced guys to check out the parts.

 

[BSwayze]

Justin, if you have depressed areas around your dimples, you are definitely under-dimpling. I made this mistake early on with my empennage and my tech counselor straightened me out. I paid him a visit at his shop and he trained me in the art of dimpling, telling me that I need to "beat that aluminum into submission". I was being too cautious and careful. He used a C-frame and hit each dimple twice, harder the 2nd time. His rivets were dead flat with no distortion of the surrounding sheet, just gorgeous. And mine have been that way ever since.

I should add, I do have a C-frame, but for much of my work I used a DRDT-2 Dimpler. I set the adjustment tight enough so that when I pull the handle, it actually bends the arms apart on the unit a bit, and I hit each dimple twice. There's only a very subtle difference between the results compared to the C-frame, which is a bit superior overall, but for the most part you can't tell the difference. The DRDT works great if you set it up correctly.

Before:

After:

Practice on some scrap material. It won't take long to see the difference.