!%$#(*&^%$--ah--does anybody use bondo?

mark schoening · #1 10-09-2006, 12:10 PM

OK--I'm a klutz! on tail, flush set slipped and I now have small dent next to rivit. Wait to paint time or ? I can't think of a fix.

PainterJohn · #2 10-09-2006, 12:18 PM

Your best bet to fill that ding is to use a good body filler not "Bondo" brand but use Evercoat or 3M body fillers. Pirana and Icing putties or surface glaze is not for filling dings, only pinholes in fiberglass or in other minor imperfections. Most automotive paint supply places carry the good stuff. AutoZone does not (well in my area). All of the "heavy" fillers work best (and should always be applied) to bare metal, besure to sand the area with atleast 80 grit before you wipe it on there, otherwise it will flake later on.
Good luck
John

Mel · #3 10-09-2006, 12:20 PM

Bondo is heavy. More modern fillers use microballoons. Just leave it for now and catch them all just before paint. There will be more.

mark schoening · #4 10-09-2006, 12:39 PM

OK, thanks for info, guess I'll store the piece so nobody can see the ding and deal with it at paint time. "there'll be more---???" urgh

frankh · #5 10-09-2006, 01:01 PM

Some fly before paint and some paint before fly.....Now you know why.....

Frank
7a painted before flight.

szicree · #6 10-09-2006, 06:24 PM

Quote:

Originally Posted by PainterJohn

All of the "heavy" fillers work best (and should always be applied) to bare metal, besure to sand the area with atleast 80 grit before you wipe it on there, otherwise it will flake later on.

I don't know that there is any agreement on whether to prime first. A lot of auto guys swear by epoxy first, then fill. To each his own, I guess.

TSwezey · #7 10-09-2006, 08:53 PM

I repair my dings right away! I hate looking at the stupid things! Also, you might forget where they all are and you will find it after its painted! You will probably make some more dings!

KTM520guy · #8 10-09-2006, 09:26 PM

If you fill it make sure you sand the area your working on REAL good. Most RVs that I have worked on that have had some type of fill work done to them have not been sanded well. Not sanding correctly will lead to the body filler popping off. I would suggest machine sanding with something in the range of 36 to 100 grit.

Funny story. I had a customer one time insist on me using "aero-dynamic filler" on his plane. I was also instucted to purchase said filler from Cessna. For $100 Cessna sent me 1qt of DYNA-LITE. DYNA-LITE is exactly the same as BONDO. Made by the same company only a different label on the can. I could have purchased the same can of filler at the local auto body supply for $10.

az_gila · #9 10-09-2006, 10:21 PM

Quote:

Originally Posted by KTM520guy

If you fill it make sure you sand the area your working on REAL good. Most RVs that I have worked on that have had some type of fill work done to them have not been sanded well. Not sanding correctly will lead to the body filler popping off. I would suggest machine sanding with something in the range of 36 to 100 grit.

Be careful here!
This is where an auto body guy can ruin your plane. In general, the FAA only allows 10% reduction in skin thickness to remain airworthy.

An enthusiastic (but well meaning) auto body guy used to working with steel can easily remove 0.0025 inch of your aluminum skins, especially with 36 or 50 grit sanding disks. Add some power tools.....

I talked to my aircraft paint shop recently about hail damage repair (another Tiger... not mine) and he said it was more expensive because they strip, and then prime, and then fill. This way, when they sand the filler smooth they can see if they are sanding through the primer layer and taking metal off. Hail damage is similar to the dings we are talking about here, perhaps shallower - he said 0.020 to 0.030 inches deep on average.

Care is needed here with the aluminum - part of the reason aircraft paint shops charge more...

Gil in Tucson

KTM520guy · #10 10-10-2006, 03:05 PM

Yes, you do have to be very careful. You want to get past the point of being lightly scuffed but stop well before the point of sanding a thin spot in your skin. Using tools like die grinders and disc sanders is a good way ruin a good skin panel. Use a DA (dual action) sander for best results.