Best method to remove paint...

Sandblast and zinc chromate immediately. leave it a couple of hours and you have wasted your time and money.

Onion Layers

Well, it really boils down to how far you want/need to go.
That, and the difference between top and bottom.
Bottomline: you want a hard, solid paintable surface to apply the paint to.
If that means taking it down to the metal - god bless you.
But really, that is not necessary.
See here:
http://www.geocities.com/tin_tonic/PaintDaze.html
IMO - itz hard enuff just sanding (no strippers - pls/not my birthday) away all the lose stuff and getting to the point where it is "ready" for prime coat - is very hard enuff.
You can spend 10s of thousands painting a metal hull.
Not to mention refairing.
Read up here:
http://www.geocities.com/alloyed2sea/Painting.doc
And here:
http://www.geocities.com/alloyed2sea/TechnicalForum.html
And then write in again for more guidance grasshopper.
Cheers!
Eric
PS - Added some "example" photoEz from "Adjournment's" latest refit - all because the first repaint did not meet owners standards.

removing paint

Hi!
We removed paint from our 38' aluminum hull last year and I can offer some advice. I'm lucky - my wife is a wonderful worker and helped me more that any woman I've heard of.
We spent hours, and hours, and hours, sanding with electric D/A sanders to get almost half the paint off. Then, the harbor master asked if we'd like to try his sand blasting attachment on a pressure washer. Great! We could save lots of time that way!
Well, maybe.... This sand blasting attachment is really a great tool in combination with a pressure washer. you don't have near the dust to contend with and when dealing with marine paints, that dust is not very healthy to breathe in.
TIP - when we used the D/A sanders, we hooked a small shop vac hose up to the point where the D/A bag attaches and that works like magic to keep dust contained! So much so, that we could sand at the doc and not get dust on other folks boats! Try it - you'll love it.
The Sand blasting had mixed results for us. It took the paint off alright, but we got too eager in doing it. When you're blasting and the hull is wet, you don't realize when you are actually digging into the fairing. We had that orange fairing on our hull and made a mess of it with sand blasting. We got alot of experience in fairing, after that, let me tell you. Luckily, we've rehab'd three old homes and have lots of plasting experience that translated well to fairing a hull.

We have used nothing but Awlgrip products. I can't say how pleased we are with them. Awlgrip paint can be rolled and tip'd, with foam brushes, and it lays down just like glass. Every product we used, from fairing, to priming, and top coat has been a pleasure. A realy pain in the wallet, but great results!

So, in a word, have patience and try D/A sanding with shop vac's attached before you plunge in with sand blasting. You'll fair much less and in the long run, it probably would be quicker. If you sand blast, be very gentle!

Best of luck! I hope you share pictures!
Tim

Did you use the sanblast attachment with sand/ Or plastic media? I'm currently refitting a 43' 1960 Roamer and have decided to go the media blasting route as opposed to (*sigh*) sanding every square inch. Just curious.

sand & water method of sand blasting

Hi Cap',

i blasted with a mix of sand and water, as provided by a pressure washure with a sand blast attachment. It worked rather well. A 2500 psi pressure washer pushing water along with sand it picks up via a hose stuck into sand bags.
I think you'll be fine - just be gentle and check that you aren't going "too far." You'll surely get enough sanding afterwards, to prep it for paint and in whatever fairing and between coat sanding you do.

Sure look forward to postings of your progress.
Good luck
tim

Hi,

Paint removal - depends on area.

In case of a lot sq.m(ft) grit blasting is the best solution,
but certain (ecological) restrictions may apply (depends on local authorities).

Hydroblasting is another option in this case. All dust will be removed through the suction hose attached., but... more expensive.

In any case, surface preparation standard ISO 8501-1 to be followed.

There are a few blasting standards (from low to higher): Sa-1.0 ; Sa-2.0 ; Sa-2.5 ; Sa-3.0 ;

However, a different type of grit has to be used (compare to steel surface preparation) while treating Alu-surfaces.

But, never start blasting without cleaning first with high-ressure fresh water !!!
Otherwise, salt / bacterias will penetrate into metall surface, after that a paint lawer will be applied, and then ... wasted paint / time, etc...


Please contact Your paint manufacturer for an advise. They can send a trained person (inspector).

Hope this information will useful,

Best regards,

Andrei