Sandblasting your tin???

I'm thinking of sandblasting all the old junk off my boat, the previous owners have used several layers of putty, epoxy, goop whatever over the years to stop the rivets from leaking. Now all the old "fixes" are peeling up and leaking again. I'm going to fix all the leaks right. Also the old paint is fading and rubs off so I want to remove it, and repaint from bare metal.

So my questions are.
1. What media did you use to blast your boat?

2. What pressure did you use to avoid warpage?

3. Any suggestions or things to avoid?

4. Did you buy a sandblaster just for this project? If so what did you get? I'm thinking of a spot blast gun, or a small (40#) gravity feed system. I hear the spot blaster has less clogging, but the gravity feed doesn't need to be refilled as often... Your opinions on these?

Thanks in advance for any help.

bpoulin said:

I'm thinking of sandblasting all the old junk off my boat, the previous owners have used several layers of putty, epoxy, goop whatever over the years to stop the rivets from leaking. Now all the old "fixes" are peeling up and leaking again. I'm going to fix all the leaks right. Also the old paint is fading and rubs off so I want to remove it, and repaint from bare metal.

So my questions are.
1. What media did you use to blast your boat?

2. What pressure did you use to avoid warpage?

3. Any suggestions or things to avoid?

4. Did you buy a sandblaster just for this project? If so what did you get? I'm thinking of a spot blast gun, or a small (40#) gravity feed system. I hear the spot blaster has less clogging, but the gravity feed doesn't need to be refilled as often... Your opinions on these?

Thanks in advance for any help.

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I think you would be wasting your time with any of those small sand blasters it would literally take you all day to do a 14 foot jon and even then it most likely wouldn't be done very well. Your best bet is to find someone who does sandblasting professionally it would only take them 30 mins at most to do a whole boat and you would come out cheaper than buying one of those guns and the media to go in it. Also what size compressor do you have to do this with? Even those small guns take a pretty big compressor to do any kind of continuous blasting.

I would not blast aluminum. Use a propane torch on the putty and expoxy and it will come off. Use aircraft stripper and saran wrap for the paint. Probably take less time and you'll end up with a better result vs. sand blasting which can warp the metal, makes it thinner, and can be a real pain to paint over.

Jamie

I blasted my boat and had zero problems. I see tons of posts about blasting being a bad thing, warpage, etc. To be honest, if you use a little common sense when you do it, I really dont see how its possible to damage the boat. I blasted my boat to bare aluminum in about 15 minutes. How you build enough heat to warp the aluminum is beyond me. As far as the notion that its harder to paint, I cant quite understand that one either. Its leaves a pretty agressive finish which makes bonding simpler than the super smooth finish you get when you use stripper.

I agree that you would probably be wasting your time with the little blasters. I have a buddy with a blaster. We used the finest media I could find. Obviously you dont want to spend a bunch of time in one area but it peels the paint off so fast you dont need to. As far as the settings, I'm not sure, he set it all up and I blasted away. Zero warpage on my boat and my aluminum isnt any thinner than it was before I started.

I'd like for someone to post pics of warpage on an aluminum boat due to sandblasting. Everyone seems to have that opinion yet there dosnt seem to be any evidence anywhere. I and several others on this site have sandblasted with zero problems. As far as I'm concerned, its the best method to completely strip your boat!! Sure the aircraft stripper works but ask the guys that have gone that route about it. Its not a simple task and its super messy. I can sandblast a boat before you get your can of aircraft stripper open and get your safety gear on!!

Bassblaster, I looked at your build and I think you had access to either a good blaster setup (to do a Kenworth farme) or thin paint, possibly both. Your blast job turned out very well for 15 minutes of effort and I think steelflex would hold to it. It's been my experience when blasting that some of the media stays embedded in the metal causing most paints to lift sooner or later.

I think a mickey mouse blaster vs. layers of material, or even a good heavy duty blaster against layers of paint on thin material won't turn out very well.

Ranchero50 said:

Bassblaster, I looked at your build and I think you had access to either a good blaster setup (to do a Kenworth farme) or thin paint, possibly both. Your blast job turned out very well for 15 minutes of effort and I think steelflex would hold to it. It's been my experience when blasting that some of the media stays embedded in the metal causing most paints to lift sooner or later.

I think a mickey mouse blaster vs. layers of material, or even a good heavy duty blaster against layers of paint on thin material won't turn out very well.

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It was a large industrial type blaster hooked up to one of those large compressosr that you pull behind a truck. There was 3 or 4 layers of paint, cant really remember now. I definately agree the little small blasters would probably be a waste of time.

I guess just keep checking into my build and we'll see how well everything sticks too it. Its been too darn hot to actually work this week. I have a few problem rivots to deal with, then its steelflex for the bottom and paint on the sides!!

BassBlaster said:

I blasted my boat and had zero problems. I see tons of posts about blasting being a bad thing, warpage, etc. To be honest, if you use a little common sense when you do it, I really dont see how its possible to damage the boat. I blasted my boat to bare aluminum in about 15 minutes. How you build enough heat to warp the aluminum is beyond me. As far as the notion that its harder to paint, I cant quite understand that one either. Its leaves a pretty agressive finish which makes bonding simpler than the super smooth finish you get when you use stripper.

I agree that you would probably be wasting your time with the little blasters. I have a buddy with a blaster. We used the finest media I could find. Obviously you dont want to spend a bunch of time in one area but it peels the paint off so fast you dont need to. As far as the settings, I'm not sure, he set it all up and I blasted away. Zero warpage on my boat and my aluminum isnt any thinner than it was before I started.

I'd like for someone to post pics of warpage on an aluminum boat due to sandblasting. Everyone seems to have that opinion yet there dosnt seem to be any evidence anywhere. I and several others on this site have sandblasted with zero problems. As far as I'm concerned, its the best method to completely strip your boat!! Sure the aircraft stripper works but ask the guys that have gone that route about it. Its not a simple task and its super messy. I can sandblast a boat before you get your can of aircraft stripper open and get your safety gear on!!

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Its not the heat that warps the metal it the peening of the metal by the blasting media causing the material to stretch more on one side than the other. That's why on classic car restorations soda blasting is recommended because the soda is fine enough not to peen the metal but will remove paint. On an aluminum boat I would be less than concerned about alittle warpage.

blasting is the way to go as long as you use the correct media. soda blasting is the most popular. you can take the finish off of a soda can without damaging the can so dont worry about the boat. you air compressor needs to have at least 16 cfm to be effecient. bill

and that's the rub, 16cfm isnt a small compressor.

Thing about aluminum, it comes in a variety of thicknesses, gages. Ones result could dramatically be different then anothers due to teh aluminum thickness. I once warp the crap out of a car fender by sand blasting it. At my former job, we sandblaster steel all day long, extremely noticeable finish after blasting. Made paint stick like crazy (meaning plenty of dimples in the steel for eth paint to grab onto).

Have you thought about a pressure washer?

If you have access to a good quality blaster, a big compressor, the proper media, and your boat isn't paper thin .... then go for it!

I have found that a stainless steel wire wheel mounted on a basic angle grinder is the most economical way to strip a boat. It takes some time, but does a very good job and won't damage the aluminum.

I know what you're thinking ... "that will take me FOREVER".

Spend an hour a night working diligently, and in a week you'll have a shiny bare boat ready for primer.

MrSimon said:

If you have access to a good quality blaster, a big compressor, the proper media, and your boat isn't paper thin .... then go for it!

I have found that a stainless steel wire wheel mounted on a basic angle grinder is the most economical way to strip a boat. It takes some time, but does a very good job and won't damage the aluminum.

I know what you're thinking ... "that will take me FOREVER".

Spend an hour a night working diligently, and in a week you'll have a shiny bare boat ready for primer.

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wire wheel/grinder is the way I cleaned my trailer. Worked like a champ and didn't take long. A good wire wheel will eat through just about anything in no time. Harbor Freight has inexpensive grinders and wire wheels, if you don't mind made in China tools.

Yup, I get my wire wheels from Harbor Freight.

I only use stainless for aluminum and I can get a good SS wire wheel for about 5 bucks. They aren't the best quality in the world, but two of them will get me through an entire 14' tin.

I really like the wire cup design better than the wire wheel. The ones at HF are perfect. Not too abrasive that it will hurt the aluminum, but enough that I can cut through many layers of paint if I need to.