Abrasive Blaster

[SpeedThrills]

https://www.harborfreight.com/18-oz...W4fb6yQNRctddt27QZK6hpmX6PhsrIXoaAhaTEALw_wcB

I want to strip the paint off my heads and block. I don't want to tank them, because I live no where near a shop that could do it, and the engine is ready to assemble It doesn't need any machining. It was apart to have the crank repaired after spinning a bearing, and it was painted yellow (not my preference) by the PO years ago.

Will media blasting with baking soda be aggressive enough? I have to do it in my driveway and (I think?) I can just hose it away. I'm thinking of the above gun. I made one years ago, but as I recall, it was a pain to operate and ate a lot of baking soda.

I've tried a wire wheel in a drill, that's tedious to say the least.

 

[niceolddart]

Clean it as best you can with a scrub brush & compressed air, prime w/self-etching primer & paint it. I would not use any kind of blasting material at all. It could get in spots that you may not see to remove. A good cleaning & self-etching primer should be plenty adequate for painting the block & heads.

 

[SpeedThrills]

It's going to get scrubbed, up and down, in and out, but I can see something getting stuck. I have heat paint for it. Is there such a thing as high heat primer? I've never primered an engine before.

 

[niceolddart]

I'm pretty sure VHT has what you need, I just don't think any kind of abrasive blasting would be good for cleaning the block & heads. Hot tanking is the way to go. It's too bad that's not an option for you though.

 

[toolmanmike]

I wouldn't blast it and that small blaster is more of a spot blaster than anything. You also need a good compressor to make it work. The media get's all over and it's tough to get it out of places it doesn't belong.

 

[70SwingerGuy]

I agree with @niceolddart and @toolmanmike , for one, that blaster is only a spot blaster and would take a long time to blast an entire motor, and two, blasting media whether it be sand or soda, or whatever, will get EVERYWHERE and no matter how much you think you have cleaned it, there will still be some left over hiding. Trust me, Ive learned this from experience.

 

[Texas Red]

I agree with @niceolddart and @toolmanmike , for one, that blaster is only a spot blaster and would take a long time to blast an entire motor, and two, blasting media whether it be sand or soda, or whatever, will get EVERYWHERE and no matter how much you think you have cleaned it, there will still be some left over hiding. Trust me, Ive learned this from experience.

I second and third everyone. No media blast. Grit will be everywhere.

 

[70SwingerGuy]

I just got my speedometer back from being repaired/restored, and was told that they actually found some fine grit sand in it! Obviously a PO had been blasting somewhere, and like I said, it gets everywhere.

 

[SpeedThrills]

These replies are exactly why I posted here! Thanks, everyone!

I'll wire wheel it in the bad spots, and prime/paint it.

 

[YY1]

That self contained blaster is barely adequate for a bracket.

You will be filling the media holder many, many, many times to do a head.
You will lose count.

I tried using one to do a relatively clean wheel once.
Gave up after I lost count of the the times I had to stop and refill the media.

Something like this will be much more useful-

 

[toolmanmike]

That self contained blaster is barely adequate for a bracket.

You will be filling the media holder many, many, many times to do a head.
You will lose count.

I tried using one to do a relatively clean wheel once.
Gave up after I lost count of the the times I had to stop and refill the media.

Something like this will be much more useful-

View attachment 1716399998

And you will need a 5 horse 60 gallon air compressor to run it. (minimum)

 

[YY1]

And you will need a 5 horse 60 gallon air compressor to run it. (minimum)

I'd recommend 12 CFM or more.

Some 5HP 60 gallon units are only 8 CFM @90 psi.
That's NOT enough.

 

[toolmanmike]

I'd recommend 12 CFM or more.

Yes sit. It takes a lot of air.

 

[Righty Tighty]

These replies are exactly why I posted here! Thanks, everyone!

I'll wire wheel it in the bad spots, and prime/paint it.

I recommend taping off any areas you don't intend to strip, especially oil/coolant passages. Even using a wire wheel, you know just like the rest of us that those little wires constantly break off. Add to that all the paint & gunk you'll be releasing. I personally wouldn't want any of that to make its way into a ready-to-assemble engine.

I'd recommend 12 CFM or more.

Some 5HP 60 gallon units are only 8 CFM @90 psi.
That's NOT enough.

Absolutely. Blasters (even small ones) use a LOT of air. My last compressor was 24 CFM, and while it was decent, it still cycled a lot more frequently than I preferred when using the blast cabinet for any extended period of time. Sadly, most household compressors aren't up to the task of abrasive blasting. Even the "big" ones.

 

[340sport]

I would recommend spraying epoxy rather than the old school self-etching primer, just my 2 cents. You CAN use etching primer or something like OSPHO, but I feel epoxy does a far better job and loves heat. You have options, now figure out what's best for you and your situation and get at it.

 

[YY1]

I recommend taping off any areas you don't intend to strip, especially oil/coolant passages. Even using a wire wheel, you know just like the rest of us that those little wires constantly break off. Add to that all the paint & gunk you'll be releasing. I personally wouldn't want any of that to make its way into a ready-to-assemble engine.


Absolutely. Blasters (even small ones) use a LOT of air. My last compressor was 24 CFM, and while it was decent, it still cycled a lot more frequently than I preferred when using the blast cabinet for any extended period of time. Sadly, most household compressors aren't up to the task of abrasive blasting. Even the "big" ones.

I'm surprised a 24 CFM stopped at all.
I have an industrial 32 CFM unit and when I'm blasting in the cabinet, it runs non-stop until I let up.

That's why I always caution against using HP or especially gallon capacity as a measurement of blasting capability.
My 80 gallon tank is almost instantly emptied, once I start.
CFM @90 is KING of judging a good blast cabinet compressor.

...and 12 is a baseline starting point for occasional use.

Unfortunately, that's right at or just above the number most all "big box" hardware stores have on hand as their largest unit.

 

[Righty Tighty]

I'm surprised a 24 CFM stopped at all.

I think when I had that compressor, I worked intentionally slowly because I didn't want to overwork it. I'm at 47 CFM now, and I just flip the switch to manual until I'm done. But I also try to let a good stack of parts pile up before blasting. The way my shop is set up, I need to wheel the cabinet out for use. So it's annoyed my to do that just for one or two parts.

 

[1MeanA]

I'd recommend 12 CFM or more.

Some 5HP 60 gallon units are only 8 CFM @90 psi.
That's NOT enough.

A real 5 hp compressor will be closer to 4 cfm/hp. That's how you know when there is marketing baloney going on.
I ran my pot blaster with a 5 hp 80 gallon. Using cheap crushed glass was the only way to go. They won't sell blasting sand up here any more along with good stripping gels. Even my blasting cabinet makes the compressor run nearly full time.

 

[SpeedThrills]

I've decided to wait until the engine is assembled to prep it for paint. It'll be much easier to tape off whatever needs to be protected. Kind of a no-brainer in hindsight.

 

[rbkt65]

You will never get all the sand out. I blasted my wagon and we blew and blew and blew. When we made the 1st pass, I got called to the tower and handed a broom, 3 times. COULD GET CAUGHT IN AN OIL HOLE.

 

[Demonx2]

^^^handed a broom?

Not that there's funny!!