Sandblasting with Glass Question

[af226]

I have a Pricessauto/Harbor freight siphon style blasting cabinet. I have glass media in their right now. I tried cleaning one of the old valve covers and the media chewed it pretty hard. I do not know the grit of the current media as it was given to me by a friend in a generic bucket. I have searched the intewebs, but cant find the proper grit glass to get the satin finish I am looking for.

Does anyone have experience with grit and PSI for a satin finish on aluminum? I have access to this locally:

https://www.princessauto.com/en/55-lb-glass-bead-blasting-abrasive/product/PA0009075524

Says 60-80 grit. That is the smallest grit I can find.

Any advice is appreciated.

Brad
af226

 

[af226]

I suspect that I may have this:

https://www.princessauto.com/en/50-lb-greengrit-crushed-glass-blasting-abrasive/product/PA0008223794

Says 20-30 grit which is way to aggressive!

 

[jpdevol]

I use 175-325 sieve glass beads @ 30-35psi in vapor blast for finishing aluminum - your cabinet may be a bit different, but I think that's the media you're after. Crushed glass ok for stripping paint on steel.

 

[af226]

I use 175-325 sieve glass beads @ 30-35psi in vapor blast for finishing aluminum - your cabinet may be a bit different, but I think that's the media you're after. Crushed glass ok for stripping paint on steel.
View attachment 235700

https://www.grainger.ca/en/product/GLASS-BEADS,50LB-,170-325-MESH,NO-13/p/AGCGLB17032550

This looks like the same product?? Would this run in a siphon feed blast cabinet?

My cabinet: https://www.princessauto.com/en/floor-model-abrasive-blasting-cabinet/product/PA0008046492

Is this only good for vapor blasting? Or will it work in a dry blast cabinet?

Thanks

 

[5twins]

I use the 80 grit in my cabinet and I think it's what you're after. But, I don't do a lot of parts that are going to be polished, mostly I do rough castings like cylinders and heads. For parts I'm going to polish, I usually use Roloc discs or sand them to remove corrosion. The flanged alloy rims are something I'd like to try blasting on though. They won't fit in my cabinet but a buddy has a bigger one that will take them.

Just a heads up and warning - don't blast any internal engine surfaces. The glass beads will embed into the alloy and they won't wash out. But, once you run the engine and it heats up, they'll be released and wreak havoc on your bearings.

 

[af226]

I use the 80 grit in my cabinet and I think it's what you're after. But, I don't do a lot of parts that are going to be polished, mostly I do rough castings like cylinders and heads. For parts I'm going to polish, I usually use Roloc discs or sand them to remove corrosion. The flanged alloy rims are something I'd like to try blasting on though. They won't fit in my cabinet but a buddy has a bigger one that will take them.

Just a heads up and warning - don't blast any internal engine surfaces. The glass beads will embed into the alloy and they won't wash out. But, once you run the engine and it heats up, they'll be released and wreak havoc on your bearings.

Thanks for the heads up. I am looking to blast most of the old motor and have seen online the "Satin" finish not and nice as vapor but still much better that 45 yr old dirt and grime. I don't really want a polished finish. just cleaner and Aluminum finish. Do you think the 60-80 grit would work??

Brad
af226

 

[af226]

Stainless Steel looks like a nice finish but the media is $400 for 20kg

 

[RC4MAN]

You might adjust air pressure down

 

[5twins]

Yes, I think the 60-80 grit should be fine. Here's some "before and after" shots of parts I've done in mine .....

 

[af226]

Yes, I think the 60-80 grit should be fine. Here's some "before and after" shots of parts I've done in mine .....

View attachment 235707

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View attachment 235709

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View attachment 235714

Nice tx. I will try the 60-80 at a lower pressure.

 

[cycleranger]

I use ~80 grit glass beads in my leaky HF cabinet. Running about ~15 cfm@90psi.
No issues cleaning aluminum or steel, although it can be a little slow to remove thicker paint.
I don't usually use the glass beads on stuff that I'm planning to polish.
For cleaning carbs and delicate bits I use baking soda, it's a little slow sometimes but it's cheap in big bags from Costco.

 

[WideAWAKE]

I use ~80 grit glass beads in my leaky HF cabinet. Running about ~15 cfm@90psi.
No issues cleaning aluminum or steel, although it can be a little slow to remove thicker paint.
I don't usually use the glass beads on stuff that I'm planning to polish.
For cleaning carbs and delicate bits I use baking soda, it's a little slow sometimes but it's cheap in big bags from Costco.

HF sells a big bag of “heavy grit” soda that give a great finish on carbs

 

[Niels B]

I do a lot of blasting almost only with glass beads grid 170-325 if you want satin finish. I use it in a vapor honer so it’s mixed in with the water -
This is what I use @ 80-90psi, you need a compressor that can handle 20-30 CFM.
https://vaporblasterforsale.com/collections/economical/products/bench-top-vapor-hone-450
Attached show one I worked on resently

 

[cycleranger]

HF sells a big bag of “heavy grit” soda that give a great finish on carbs

That would work better but I haven't seen that in stock that at my local HF and I haven't looked any further locally.
In fact a while back HF was out of stock of glass beads and I had to order a bucket from another source.
The shipping sucked on that.