Anyone sandblast their own motor themselves?

[oshanac]

I have a 1979 GS750 that has a horribly done black paint job on the WHOLE motor (minus the carbs of course) that I bought from a co-worker. I got her for $350, rebuilt (and bead blasted the carbs) and can't stand to look at the ugly paint on the motor. I'm in the middle of a very minor restore (want to get her safe and running awesomely, and was not too concerned about looks just yet) and have been thinking "Do I really want to get it all finished (don't body work on the tank/fender) and have the motor look like crap?". The local media shop charges $125.00 to blast and prep a frame (motor maybe more?) but I'm a big DIY'r.

[Nessism]

I'd like to strongly discourage you from considering blasting the engine if it is assembled. No matter how careful you are the blast media will get though. If you choose to ignore this advice, use something like soda media since it's less abrasive.

When rebuilding the engine on my GS1000, I blasted the engine parts after the parts were broken down. Worked great to remove all the corrosion and gave the metal a good surface to paint on top of.

[tas850g]

so it's safe to blast, say, the valve cover? Any particular type media?? I have access to a sand blaster at the college i work at and would like to do something like this to work on cleaning it up a bit.

[sachsaca]

My neighbor builds cars, he was telling me he doesn't use sand for this due to the heat it generates in the specific area and it changes the temper of the metal. Knowing that you will not be sand blasting thin car metal I am curious if it holds true here. He uses pecan shells and walnut shells and get the same results. Just a thought

[Nessism]

Glass bead is good. I've used other media including elcheapo Play Sand available at Home Depot as well - used this on my engine cases with a total loss blast gun. Now I use glass bead because I found this on ebay for $45.

[oshanac]

I definately don't want to chance sand getting in my motor. Woudn't every type of media also get in the motor then? What about spraying some kind of Aircraft Remover type on it? Would you be killing yourself with any little pieces that it didn't clear?

[Bribird]

Blasting alum

If the parts are removed and protected from blasting areas that you do not want blasted, then sand is fine. I sandblasted everything on my bike during the build...including the motor parts. But you will spend more time prepping for blasting, than the blasting itself. With sandblasting...it is very important to have all the proper safety gear...unless you like the idea of concrete lungs....Silicosis is very serious.

As for doing the motor...nessism is 100% right. If you want to blast it assembled...soda is your best bet. And you will still need to try your best to make sure it does not end up inside the motor.

Sheet metal, if you blast sheet metal with sand it breaks the surface tension and that along with the heat generated will cause the metal to bow.

[oshanac]

Dang, awesome post Bribird! Thanks. One more thing, what size HP compressor do you need for one of those Speed Blaster ebay type media blasters? I see the SCM or SMC, something like that and have no clue on what it's supposed to mean. Why dont they just say "needs 4hp compressor or larger"? Thank you!

[camp2thebell]

I would suggest just using some paint remover or that aircraft remover stuff mentioned. I did that with my engines, granted they werent painted, but it still had a lot of that protectant clear coat crap on it. Was not a very hard process.

[Zooks]

Just to be controversial - nah, just kidding, but I am going to disagree with Nessism.

I know of at least a dozen motorcycles that have had their engines blasted whilst still assembled. They are all still running and have done thousands of km's since. If you plug the holes with oily rags and then seal over the top with plates & silicon, you'll be fine.

just my 2c.

[drhach]

Just remember, it only takes grain or two to completely ruin your engine. I know this from experience by the way. Soda blasting is good because it is water/liquid soluble; Glass is not. However, you won't really be able to use soda in a system that is set up for glass. There will still be particles in it that are glass and soda has needs that most sand systems don't address. It cakes really easy and you need very dry air. It also really needs a better nozzle because it is so fine. Soda is also better in a total loss system. The soda breaks on impact and eventually gets so fine that it clogs everything. Basically, it won't work (for long) in your school's system.

[Hammered]

I gotta tell ya, bad idea to sand blast your engine assembled. There are plenty of spray cleaners and strippers that will remove the paint. And with time and a lot of elbow grease, you can Scotch pad the cases to the finish of your choosing. And even when blasting a set of cases that are tore down, you need to spend days taping and pluging holes to keep all the galleries and channels clear of blast media. If yo have the means, walnt shells does the best job for stripping and then follow up with playsand. Ive used these 2 the do the few parts Ive refinished on mine so far.

[first timer]

how do you feel about just using walnut shells? is it as critical, and scary as sand to do a assembled engine?

[hampshirehog]

Just to be controversial - nah, just kidding, but I am going to disagree with Nessism.

I know of at least a dozen motorcycles that have had their engines blasted whilst still assembled. They are all still running and have done thousands of km's since. If you plug the holes with oily rags and then seal over the top with plates & silicon, you'll be fine.

just my 2c.

Well, just to sit on the fence and agree or disagree with Nessism and Zooks........

I've just rebuilt a TS250 motor that was blasted in one lump; everything inside was knackered after 7 miles (box as well). Nice paint though

But a mate did a SOHC Honda 750 a few years back with play sand (and he wouldn't have been over-cautious knowing him) and he never had any problems.

There's a firm in the UK that will do this now and offer a guarantee.

Personally, I split the motor.

[Agemax]

i had my entire engine vapour blasted while it was apart. no masking, no plugging holes, just a dam good wash out afterwards. finish is great and so is the engine, 5 years later.
hampyhog is correct as well, there is a company in the uk that will blast your engine intact and guarantee it.