Remove primer around pop rivet

I am about to paint my aircraft after some 70hrs of flying.

When I built the aircraft 2 yrs ago I thought it would be a good idea to dip every rivet into a self etching primer for better corrosion protection. I also thought the more primer the better and didn't take great care of wiping off excess primer, see pic attached.



This is biting me now as painting over these blurbs will show....

I am wondering whether any builder came up with a great idea how to remove them efficiently.

I have been experimenting with:
- MEK on a scotchpad / rag / brush with very short bristles in a power drill
- a homebuilt mushroom / dome type dowel that fits over the rivet head and sand paper attached at the bottom. Again attached to a power drill

Neither solution allowed me to remove the excess primer in a reasonable amount of time. I will probably have to focus on the worst ones only unless I want to spend another 2 weeks on this task.

Any help / ideas are greatly appreciated.

Steffen

Acetone

Try Acetone

It cuts the self etching primer that I used

Joe Dallas

McSteff said:

I am about to paint my aircraft after some 70hrs of flying.

When I built the aircraft 2 yrs ago I thought it would be a good idea to dip every rivet into a self etching primer for better corrosion protection. I also thought the more primer the better and didn't take great care of wiping off excess primer, see pic attached.

This is biting me now as painting over these blurbs will show....

I am wondering whether any builder came up with a great idea how to remove them efficiently.

I have been experimenting with:
- MEK on a scotchpad / rag / brush with very short bristles in a power drill
- a homebuilt mushroom / dome type dowel that fits over the rivet head and sand paper attached at the bottom. Again attached to a power drill

Neither solution allowed me to remove the excess primer in a reasonable amount of time. I will probably have to focus on the worst ones only unless I want to spend another 2 weeks on this task.

Any help / ideas are greatly appreciated.

Steffen

Click to expand...

They make scotchbrite pads that you can chuck up in your drill or die grinder. Get the harder pads (Gray?) and hit all your rivets with two passes, one at 90 degrees to the other. That should remove any residue and provide a good bite for the paint.

It would seem that paint shops deal with this problem frequently since they have to remove the old paint job first. When my Cherokee was painted years ago I remember some super solvent that took the plane to bare metal in hours. See if you can get a paint shop to sel you some or at least ID what they use.

I would opt for chemical stripper and a fine brush that is compatible with Aluminum and stay away from any power tools around the rivets.

Wheel and leg fairings

I see you have a 12 and I'm talking about a 7, but may apply to you also, especially the cowl area. One thing that has plagued me is the rivets that hold the leg fairings together - not a problem for a 12. After flying unpainted for many months, engine oil "fog" inside the engine compartment also extended down the gear leg fairings. The rivets that attached the fairings at the aft edge were impossible to clean prior to painting, and the paint shop worked a looooong time on the fairings as well as the rivets on the cowl - they are familiar with the potential problem. The paint on the fairings almost immediately began to bleed and the paint lifted from around the rivet heads. A few of the rivets on the cowl are also bleeding. Not a crisis, but something to be aware of.

waterboy2110 said:

I would opt for chemical stripper and a fine brush that is compatible with Aluminum and stay away from any power tools around the rivets.

Click to expand...

Because?

My entire airplane was buffed with Scotchbrite pads ESPECIALLY around the pop rivets otherwise the paint tends to not stick well and pop off. FWIW, this is advice is from the expert who painted my airplane, not me.

Aircraft Stripper

I would try Aircraft Stripper for aluminum. You can get it at O'Rielly Auto parts. Although O'Rielly has a sign, not to be used on aircraft, but that's because they are a car store. They make a version for removing paint/primer from fiberglass too. I'm using it. It bubbles away the paint. You can see how to use it on YOUTUBE.

f1rocket said:

Because?

My entire airplane was buffed with Scotchbrite pads ESPECIALLY around the pop rivets otherwise the paint tends to not stick well and pop off. FWIW, this is advice is from the expert who painted my airplane, not me.

Click to expand...

Just finished painting the Cessna. The entire plane was stripped with Aircraft Stripper and the alum prep / alodyne process done with scotch brite.

So yes, you will be scuffing the aluminum to get paint to stick. My concern around power tools is removing any rivet material. I've seen it happen.

Thanks for all the advice. Paint stripper followed by an acetone cleanup turned out to be the most efficient way to remove the primer around the rivets.

Using a rotary tool / Dremel with a little nylon brush dipped in acetone also worked well, but took longer.