Sandblasting a wooden hull

[automn173]

Hello!

I have a 1966 Chris Craft Cavalier that I have owned for 4 years. I have re-done the bottom once and am planning to pull the boat out this fall and do the bottom and sides. Is there anyone who has used sandblasting to remove paint from these vintage boats. I like the idea of making the job easier, but I'm worried about potientially damaging the plywood. Any advise would be much appreciated. Here is a pic of the boat, we named her "Whoz Yer Daddy"

Dave & Susan Bullington

[automn173]

Here is a link with some pics.

http://img187.imageshack.us/slideshow/player.php?id=img187/6161/1178852598o7b.smil

dave

[Mike Vogdes]

You may want to research soda blasting instead of sand blasting, Baking soda is less aggressive and would be less likely to damage the plywood.

[brad9798]

St. Charles? Right near me ...

[automn173]

St. Charles? Right near me ...

yes, do you recognize the dardenne slew in the pics? what is the name of your boat? we are out of woodland...

Dave

[S.V. Airlie]

There are also companies using dry ice...for blasting. In theory it sounds like a good idea.. no clean up.. dry ice just goes "poof".!

[Cuyahoga Chuck]

If the hull is made with temporate zone softwood there will be bands of early wood and late wood that differ greatly in hardness. If you blast it with anything harsh the softwood will erode much faster and you will end up with wood that looks like a conture map. Blasting wood has been done but the equipment and the blasting media may be far more sophisticated and expensive than the stuff used for sandblasting.
Blasting media comes in a wide array. Sand, soda, walnut shells, tiny glass beads and God knows what else. Procede with care and don't breath any of it.

[Thorne]

Worth a search on this forum for sandblasting -- a lot of folks don't think it is a good idea for wooden hulls....

[S.V. Airlie]

Although I suggested trying dry ice, I would not use any method on a wood boat. Then again, as this thread was asking about sandblasting, answered it.
Hey it is a wooden boat... ya gotta expect to do a bit of work.:rolleyes:

[Katherine]

Use Walnut Shells

[Lew Barrett]

Sandblasting is not a good idea. Chuck explains it well, but the bottom line is that it is a Draconian procedure best reserved for metal hulls. Clearing a wooden bottom of paint is best done by a man with a sharp scraper who knows what he's about.

[WoodenBNut]

Yes, like others have said, "be very careful blasting a wooden hull with any blasting media". I would really advise against it. I have used an infrared device to heat up paint on wooden hulls and then scrape off the paint with a good pull carbide bladed scraper. I made the infrared paint remover device from a Holmes infrared electric heater. *I bought the infrared heater for $10 on eBay. The rest of the parts for $20 from Radio Shack and the instructions are at //www.makezine.com/blog/archive/2006/03/how_to_make_an_infrared_paint.html OR you can buy one ready made for $395 at www.air-nailers.com/spr/index.jsp?gclid=CIXDraHHh4wCFThhIgod2VmN6g or other places on the Internet - search on Silent paint Remover . I would also advise you to round off the corners of the pull scrapers carbide blade so that you don't accidentaly gouge your hull's plywood.
I would think you could easily strip/scrape the paint from your hull with this method and this method would not be subject to damaging your hulls wood(plywood in this case). I also found it best to have 2 people on this project. One person runs the infrared heater and the other does the scraping. It goes pretty fast. *Bring lot's of your favorite beverage!!

[Gold Rock]

Woodenbnut beat me to it. I would strongly advise against media blasting. I use a sandblaster every day. They are no nonsense tools. The main problem is control. You're seeking to remove perhaps a couple of tenths of an inch of paint without removing anything beneath it. Media blasters must necessarily put out the abrasive at a minimum volume and velocity to do what they're supposed to do, and as it turns out, this is pretty hard, at least. They're not delicate instruments, they're shotguns, and their technique is scorched earth. If you've ever looked at the surface of a steel hull that's been freshly blasted, you'll see what I'm getting at. Steel is hard enough that the amount removed isn't consequential, but wood is cotton candy in comparison. We can saw a 1/2" dowel in half in our cabinet in less than a minute with our unit, (we were bored at the time...). I could go on, but you get the idea. On top of that, I can't think of a commercial boat yard I've ever been to that would allow a media blaster to be used unless the project was completely tented. Heat gun and scraper would be my choice.

[LiveAboard]

I'm of the school that says if something is firmly stuck to the wood, and the quality of the finished surface is not important (such as the case with bottom paint), you should just leave it be. Scrape off the loose stuff and buff it down with a very fine grit sandpaper if need be, but avoid any destructive methods of removing paint from wooden boats. Aside from removing a small layer of the wood, you can create uneveness which will destroy any sense of fairness in the finished surface. Topsides I only use heat guns (or chemical paint strippers around the gas vents) to remove paint.

BTW I have a '68 CC Constellation - drop me a line sometime if you want to kibbitz :D

[S.V. Airlie]

BTW I have a '68 CC Constellation (liveaboard)

Umm Cecil is redoing one.. a '72 I think.. And you all think Airlie needed/needs a lot of work. I took a picture or two. Will look for them. Bloody frightening...
I figure a 300,000.00 job..where labor is 38.00/hour :eek::eek::eek:

[automn173]

Thanks one and all for the great advice and words of wisdom. At the end of the day, what I'm trying to do is apply the West System and some matting to the keel and maybe 2' either side along the length of the boat. I have some minor seepage along a few sections of the keel and I'm trying to seal up the bottom. I am told in order to ensure a good bond of the epoxy, I need to remove the old bottom paint and make sure the area to be sealed is completly clean and dry. Once I have her sealed up, I will prime and bottom paint so to Livaboard's point, it woun't really require removal of the entire coat of existing bottom paint over the entire bottom.

Now where did I put that scraper....???

Dave

[brad9798]

you need some help? I used to be in Woodland ... with Joe, et al.

Sharky's, etc.

Anyway, I will assist you if you would like ...

I am in WingHaven ... so not far at all if I take 370 to 94!!!!

Let me know.

[Jay Greer]

I have mentioned this before. There is a two part commercial grade remover on the market that is used for stripping paint from airplanes. Star 10 Stripper is the most effective and also mild on the skin remover I have yet to use. Very effective stuff!
Jay

[Excalibur]

Is your boat plywood lapstrake on the bottom or carvel?

[brad9798]

It is 4x8 sheets ... assuming you are asking about the boat in the first thread!

[Jon Agne]

Has anyone tried this system? Click on the bottom right frame for a video stration. Looks promising to me.


http://www.farrowsystem.com/see_it_in_action.php

[automn173]

Is your boat plywood lapstrake on the bottom or carvel?

Brad9798 is correct. It is built from Mahoghany plywood. Star 10 Stripper and the Farrow System both look very promising! Thanks guys for the tips.

Brad9798; I may take you up on the offer to help, I am planning on pulling the boat this fall, letting her dry out over the winter and starting in earnest next spring to redo the bottom and sides.

Dave

[brad9798]

Just lemme know ...