Refinishing a pedestal

[SebastienL]

Hello,

I'm about to refinish my edson aluminum pedestal. The pedestal currently has a matte black paint on it that is severely abraded in some locations, showing bare aluminum. As I was removing it for rebedding, I thought it would be nice to repaint it.

When browsing books and internet, I find two approaches at repainting aluminum. One is to etch with Alumiprep 33, then rinse with Alodine, prime with an anticorrosive epoxy primer and paint with an LPU. The other approach is to use a self-etching primer (this seems to be sold in spray cans from home depot!) and simply follow with a marine grade paint (awlgrip?).

I love the simplicity of the second, but the first one is the one described by Don Casey in "This old boat" as the approach he recommends for repainting spars.

For both methods, the descriptions are not 100% clear on whether I need to sand everything to bare metal or if I can leave non-flaking paint where it is. The black that is left on the pedestal is matte and very sound.

Thanks in advance for your suggestions.

[Lake Superior Sailor]

I suggest your second method ,you can leave good paint on but need to feather sand all bare areas and prime first. The whole thing needs fine sanding to get good bond. Don't use steel wool.Sand paper or bronze wool. then finish.....Dale

[SloopJonB]

I'd recommend you get some auto body abrasive disks for use in an angle grinder. They look somewhat like resinated plastic kitchen scrubber material. They are not too aggressive so you can feather edge solid painted areas and they leave a nice finish that only needs some Scotchbrite scrubbing to be ready for paint.

If you are going to paint it yourself, forget the two part poly paints - they are very toxic and extremely fussy & demanding. Spray all the aluminium with zinc chromate for a primer/bond coat. The stuff comes in spray cans and is usually a sort of chartreuse colour - the larger Whale Gusher pumps are painted with it, if you know their colour. ZnCrO4 is the only thing in my experience that reliably sticks to aluminium and it must be put on immediately after the final abrasive step and a solvent wipe down.

Then paint with single part poly - Interlux is good.

[Mirari]

I refinished my pedestal using the first method 7 years ago and although I have a few chips from dropping winch handles it has held up very well. No corrosion whatsoever!

[TQA]

I had a similar problem and used methed two but did not like the idea of using a spray in my cockpit so used a Berger metal undercoat that was marked as suitable for bare ali. and followed this with two coats of enamel topcoat. I did not take it down to bare ali. everywhere.

That was 18 months ago; so far so good.

[Siamese]

If you've removed it, depending on how much you disassembled it, it might be interesting to get a quote on having it powder coated. Have them prep it and coat it.

[T37Chef]

What about Powder Coating? Probably the most durable coating and since your removing it...

Its what I intend to do to mine when I remove it this Spring.

[SebastienL]

Thanks for adding the suggestion about powder coating, I didn't knew about this type of finish! A rapid search turned quite a few shops in my area (mostly involved in painting auto and bike parts).

So far, I've only received a quote from one at 200$, including sandblasting and prep. Does that seems like fair price?

[SloopJonB]

Originally Posted by SebastienL

Thanks for adding the suggestion about powder coating, I didn't knew about this type of finish! A rapid search turned quite a few shops in my area (mostly involved in painting auto and bike parts).

So far, I've only received a quote from one at 200$, including sandblasting and prep. Does that seems like fair price?

Sounds right for this area - just sandblasting one steel wheel cost over $25 twenty years ago. I had some powder coated aluminium parts on my boat that were horribly corroded UNDER the P.C. - apparently the moisture got under it somehow and left the coating practically floating on a layer of "encapsulated" Al2O3.

By the way, if you go that route, get them blasted with walnut shells or plastic media or glass beads, NOT sand - it is very abrasive and aluminium is soft.