Proposed approach to preparing for priming

[mhorowit]

In another thread you see that I took a bay down to bare metal prior to anticipating priming. I used an angle grinder with wire wheel and paint stripper and toothbrush sized wire brush where the wire wheel won't fit.

Once I get that bay primed, I'll go to the next bay. This time I plan on doing things differently and would like your opinion.

Somewhere I brought up the subject of removing everything back down to the metal and someone suggested that if the primer showed no rust marks, then it was doing its job and I didn't have to remove it; simply prime over the existing coat.

That would make life so much easier.

And quicker.

Anyone got any input? - Mike

[Ragwing nut]

Re: Proposed approach to preparing for priming

Personally I would have it blasted, check all clusters for cracking and epoxy prime. I have done it the way you are doing it, and will pay to have one blasted before I do it again. Job turns out much nicer, done way faster, and I have not had one fuselage run over $200 yet.

[mhorowit]

Re: Proposed approach to preparing for priming

Personally I would have it blasted, check all clusters for cracking and epoxy prime. I have done it the way you are doing it, and will pay to have one blasted before I do it again. Job turns out much nicer, done way faster, and I have not had one fuselage run over $200 yet.

\

Yeah; but can't store the fuse for a long time where the sandblaster/compressor is located, so have to do the max I can do at the storage location. - Mike

[Ray36048]

Re: Proposed approach to preparing for priming

I still like the Dupli Color self etch primer in a spray can to proterct the metal until you can top coat it with good epoxy. Nothing could be easier. IMHO

[Pearson]

Re: Proposed approach to preparing for priming

Mike,

Removing the paint with a wire brush on a grinder will remove the old paint and rust. But it will not get down into the pits, if there are any. And it will take a very long time.

Any rust that forms in the bay that you put the acid on will just be light surface rust for the first week or so. It will easily blast off if you sandblast.

Media blasting is the way to go, but sandblasting is a close second. Call around to metal "fabricators" in your area and ask them if they can blast your fuselage. Be sure to seal up any openings where sand can get in. They can also prime it for you on the spot. But if you have a special type of primer you want put on, you should provide that for them. Otherwise they might spray it with red iron oxide primer or something like that.

If you can't find anyone to do it for you, check the rental places for what a compressor and blasting rig would cost. If you do it yourself, you will need to get setup for it. That is another thread unto itself.

[Robert Lees]

Re: Proposed approach to preparing for priming

...Anyone got any input? - Mike

Bead blast it, use walnut chips, coconut husks, glass beads, plastic beads, silica beads, whatever removes the rust, old paint, old oil & years of collected detritus.

And if you can't do it yourself, pay a small few $$$ to get it done. Even in the expensive UK we can get a fuselage bead-blasted, etch-primed & epoxied for several hundred.

Wire brushes & so-on will not cut the mustard.

Perhaps you should ask: Anyone got a better idea than blasting? and ask them to justify it with knowledge of the longevity of the method. 20 years should do as a starter.

Rob