Sand blasting an old motor?

[jrs_diesel]

I am rebuilding my 72 6 HP, and currently have it torn down. The paint is worn, and showing aluminum in some places. Thankfully there is little corrosion to deal with.

I would like to repaint it, and would like to sand blast it before hand. I have a sand blaster at work that I am able to use.

Is it safe to sandblast as long as I mask off the important areas (internal passages, bearings, etc.)?

 

[robert graham]

Re: Sand blasting an old motor?

Maybe soda or walnut shells would be better than sand, which might pit the aluminum surfaces?...I'd definitely mask it carefully to keep the abrasive medium out of bearings, etc. Good Luck!

 

[1946Zephyr]

Re: Sand blasting an old motor?

Soda, as in baking soda?

Yes, definately mask off the top of the crank and the surface that the magplate rides on. I would make a plate to match the carb gasket and mount it where the carb goes. Then of course close off all the holes in the midsection. Also, on the side of the block, where the oil line is, I would remove that, and place some rubber caps on those nipples. Remove all the accessories and thread screws and bolts in all the threaded holes. Did I miss anything?

 

[HighTrim]

Re: Sand blasting an old motor?

I use baking soda on all my motors. Will not damage the aluminum as mentioned, where as sand will. Have heard of the walnut shells as well, but have not personally tried them. Here is a motor after soda blasting. This is a 57 Javelin

 

[nwcove]

Re: Sand blasting an old motor?

do you do the soda blasting yourself?...or take it to a blasting co.? just curious as i thought you needed specialized equipment to soda blast. ( a gun that mixes water/air/soda?)

 

[HighTrim]

Re: Sand blasting an old motor?

A local aquantaince does grafitti removal by soda blasting. I bring the parts to his jobsite, and he blasts them for me.

You can get attachments for your typical sand blasting machine that will use soda. I dont have one yet, but maybe in the future.

 

[Dman]

Re: Sand blasting an old motor?

If you are going to use it and not be a 'show motor', I don't think it's worth the hassle. You can get VERY good results with an orbital sander, and some hand sanding, and prep work.

I'm not painting expert or anything but have learned and read a lot about painting. And all the motors you see are good ole thinned Rustoleum with an enamel hardener, and some finished with a Auto Urethane coat. Key is to use an automotive type spray gun - HVLP type. They are not OEM perfect, but the Black Honda is a 76, and the white Honda is around a 79. Look pretty good for the years.

A couple examples....

 

[jrs_diesel]

Re: Sand blasting an old motor?

My engine is not going to be a show engine by any means, just an engine to push my little boat around. I would like to make it look good while I have the opportunity. Dman, your engines look pretty good. I've done the rustoleum job to a scooter and some other items around the house that turned out well.

High Trim, did you have to mask off the engine internals before the blasting? What prep work did you have to do, I assume at least to degrease the engine. I have my engine completely torn down, crank and pistons out, the whole 9 yards. I have found a guy here in town that does soda blasting so I am thinking to skip sand blasting altogether and pay to have it soda blasted.

 

[HighTrim]

Re: Sand blasting an old motor?

I honed my cylinders after I soda blasted, and didnt really mask anything as it is completely torn down as you can see.

The good thing about soda is, it completely dissapears after washing. Wash the part off after blasting and you will be good to go.

Sandblasting is different. If you dont get every little piece out it could cause trouble.

The only time I would sand blast would be with the Old Iron. For aluminum, soda is king.

EDIT: Forgot to mention, I dont really spend a whole lot of time cleaning, I get the bulk off before blasting but the blasting takes care of most of it.