How To Remove Paint From Cast Aluminum

Joined: February 2009
Posts: nine
Likes: 0, Points: 0, Legacy Rep: 10
Location: SF Bay Surface area

mosk22rte Junior Member

If you lot've seen my other previous threads, you lot know I'm "restoring" a 12' Klamath aluminum Five gunkhole. It's a minor angling gunkhole that I only await to use in freshwater. Really, what I'thousand doing is more like "fixing it up" than a true restore.
Yesterday, I finished removing the rest of the rotted plywood demote seats and the styrofoam, so the hull is substantially stripped down to its skeleton.

Today, I pressure washed the hull. What'south left are the remains of the factory pigment job and a second crappy spray paint job applied past a previous owner.

Today's question: can I do a decent job in my driveway removing the residual of the old paint and creating an acceptable surface for some new paint? From my reading, it seems that in that location'southward a lot of scientific discipline to properly removing paint from aluminum and prepping the surface for a new coat, and while I want to practise a good job, I don't want to make this my life's piece of work; this is a angling boat, not the ceiling of the Sistine Chapel.

I sympathise that without proper surface prep a new coat of paint won't adhere properly, and without removing the old coats I'g not going to get a better result than the previous owner. I'm sort of interested in hearing how others have handled this dilemma.

Finally, has anyone taken a small aluminum boat to a body shop or like, to have information technology media blasted and primed? Not sure how much such that would cost, but I hate painting and prep work, so having information technology done professionally is somewhat appealing.

Thanks,

Jeff
Joined: Jun 2007
Posts: 2,640
Likes: 124, Points: 0, Legacy Rep: 1802
Location: Brisbane

Landlubber Senior Member

Sorry Jeff, there are no shortcuts to doing the job properly.
However, the employ of sandpaper and h2o based acrylics will make the boat look pretty again and the price volition exist minimal. Try to employ a vinyl etch or zinc chromate on the raw alloy before painting.

At that place is no way ypou can do the job correctly and not overcapitalise the boat, blasting tin plate is usually out of the question for both costs and practicality (also sparse).

Go with the acrylic gloss firm paint mate, it will look presentable, toll minimal, and get the bloody thing back to the water asap.

I tin can go on and on about how to do the job correctly, merely the toll will exist absurd, even doing everything yourself.
Joined: February 2009
Posts: 92
Likes: 0, Points: 0, Legacy Rep: 2
Location: Idaho

drmiller100 Junior Fellow member

any automotive paint shop will have "airplane paint removal" chemical.
spray it on, wait a few minutes, wipe it off, then hose it all downwards.
Joined: Sep 2007
Posts: 137
Likes: 1, Points: 0, Legacy Rep: 20
Location: Western Massachusetts

Lt. Holden Senior Fellow member

I think DR is on the right runway. And since your boat is welded, if you should have whatever demand to sand, ther are no pesky rivets in the way. Practice you have any spray equipment? You will demand "cocky-etching" primer to prime the bare metal and it is much cheaper by the quart than in droplets cans. If the acrylic house paint volition attach properly that is the most economical route, aluminum "automobile trunk" paint is very expensive for what yous are trying to accomplish.
Joined: February 2009
Posts: ix
Likes: 0, Points: 0, Legacy Rep: 10
Location: SF Bay Expanse

mosk22rte Junior Member

Thanks, guys. Didn't think there was a shortcut, per se, just trying to find the best way to do this given my situation.
Hmmm...I have a decent air compressor simply no spray gun, though the cheaper ones aren't too expensive, IIRC. Not sure how much skill I'd demand to use ane, but I assume what I'thousand trying to do isn't too difficult. Still, I may need to call around to some friends and see if I can call in a favor or two.

Whatever other tips/suggestions? The ones offered so far are helpful.

-Jeff
Joined: Sep 2007
Posts: 137
Likes: 1, Points: 0, Legacy Rep: 20
Location: Western Massachusetts

Lt. Holden Senior Fellow member

A good, inexpensive, HVLP (high volume low pressure) spray gun I have used for half-dozen years is a Porter-Cable that I paid effectually $lxx for; I' ll check on the model number. Spray painting isn't difficult, read the pigment mfr.'s instructions carefully and adjust your settings on a piece of cardboard; note that you may have to modify the settings on vertical surfaces to avoid runs.
Joined: Nov 2003
Posts: xix,133
Likes: 489, Points: 93, Legacy Rep: 3967
Location: Eustis, FL

PAR Yacht Designer/Builder

Rent a soda ash blaster and remove the pigment without harming the aluminum. A good washing afterward and you're gear up for paint prep.
Joined: Feb 2009
Posts: 4
Likes: 0, Points: 0, Legacy Rep: 10
Location: Commonwealth of australia

Ruddy Dog New Member

Hi Jeff
I had my aluminium power catamarans painted and information technology became "like new".

I took it to the local sand blaster $400, then direct to the paint shop washed with 2 pack paint ... scrap expensive but the boat is valued now at $35k compared with $20K before.

It is a big gunkhole but with aluminium you can rejuvinate them relatively easily.

Prices are obviously Australian, simply if your hull is sound, information technology may be worth the endeavour.

Geoff
Joined: May 2009
Posts: one
Likes: 0, Points: 0, Legacy Rep: x
Location: North Carolina

LadyT-Bird New Member

I am a 59 yr. old adult female. Last week I bought a fourteen ft. aluminum boat that had several old chipping paint jobs on it. I went to Dwelling house Depot and got 2 cans of Klean Strip (8.99 ea.) Look for the ones that have the costless spray bottles attached. Sprayed on sides, and brushed on expanse under lip. Waited the fifteen min. suggested, and so used my ability washer to rinse off paint. I was amazed. It took paint off to the bare aluminum. The merely problem I encountered, nether some of the layers there were plastic #'southward stuck on. I used razor to remove these, and sprayed these spots again. Power washed and ALL pigment was gone. Then I used Elementary Dark-green straight out of the bottle and done the boat. Then power washed again. My boat looks similar a new aluminum gunkhole. I think I will use an aluminum polish and leave it as is. It really took the pigment off. Good Luck
Joined: November 2003
Posts: nineteen,133
Likes: 489, Points: 93, Legacy Rep: 3967
Location: Eustis, FL

PAR Yacht Designer/Builder

If you really want to brand the aluminum await good, take a buffer to information technology. You tin get a almost mirror finish if y'all so desire, with just elbow grease (okay buffer grease). Conversely, you could take it to an automotive item store (where they buff upwardly cars) had have them do it. Buffing does require some skill, some chemicals and of class a buffer. If the aluminum is left to the elements, it volition oxidize, develop a chalky blanket and get quite dull and change color, quite a fleck. Buffed and well maintained wax volition prevent this. Yous could also clear coat the aluminum once you get it looking adept.
Joined: Mar 2002
Posts: 951
Likes: 35, Points: 0, Legacy Rep: -12
Location: British Columbia

Brent Fellow Member

A friend, who worked on aluminium boats all his life, including America's cup boats, said he found the merely reliable way to become paint to stick to aluminium was a light sandblasting. He tried "Etch " primer on his ain boat and institute it softer than than the epoxy he put over it. He said the epoxy over sandblasted decks worked much improve.
Brent
Joined: Apr 2009
Posts: 72
Likes: 17, Points: 0, Legacy Rep: 171
Location: connecticut

fasteddy106 Junior Fellow member

Make sure you stay away from annihilation with steel in it to remove the paint. Information technology volition embed in the aluminum and screw upwards your topcoat. Y'all tin get a two part epoxy from any marine supply house once yous clean off the former paint and wash it properly. Exist sure to stay with aluminum specific prep cleaners and primers. For a top coat use the real stuff, the divergence in price isn't worth doing the job twice, get a marine paint suitable for your needs. For howto, you can go to Jamestown Distributors spider web site, be sure to put aside some time though, the amount of info there can exist obsessing for anyone interested in DYI projects.
Joined: Mar 2007
Posts: 88
Likes: 5, Points: 0, Legacy Rep: 72
Location: Madisonville, LA

mudman Junior Member

I can't believe no one has mentioned Alum-brite. Strip the paint with a pigment stripper and so ALUM-BRITE before paint. Puts a nice profile on the aluminum. Very corrosive.
Pull a fast one on is to not let the Alum-brite dry. Just put information technology on there and wait a few minuites, and then pressure launder it off. The paint will stick to the profile very very well.
Joined: Aug 2004
Posts: 3,192
Likes: 208, Points: 63, Legacy Rep: 2054
Location: Australia

MikeJohns Senior Member

Sodium hydroxide (NaOH), likewise known every bit lye and caustic soda cleans end surface etches aluminium very well. Nigh of the commercial products are just NaOH with a brand name. Dissolve the caustic soda into h2o and paint brush on. Wash with water to finish the etching.
Joined: May 2009
Posts: one
Likes: 0, Points: 0, Legacy Rep: 10
Location: Southward Florida

stextor New Member

Your decision and results
mosk22rte, Your post summed up nicely the piece of work I am now tasked with. May I ask a few followup questions?

one What were the methods you decided on to remove the paint, prime it and pigment information technology? Mentioning brand names are skillful with me

ii. How did it turn out?

three. Whatsoever tricks? Lessons learned? What was the most hard part?

Thanks

Forum posts represent the experience, opinion, and view of private users. Boat Design Internet does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always use and consult appropriate professionals. Your circumstances or experience may exist different.