Sand blasting? Bead blasting?

[Tom Kitta]

Usually you can get a decent 5hp compressor for around $300. For $500 you can get very nice one in usually 7.5hp range, gently used etc.

Frequently larger compressors in the 10hp range don't cost much more then 5hp ones - or the same $. For same condition.

$1600 plus fees = 2k for the 20hp compressor was a steal given that it was more or less new - a demo from the looks of it (it was like 2017 production year). Someone paid like .15c on a $.

Actions have plenty of these around - every larger auction has few 5h - 10hp compressors. For that amount of $$$ there is no reason for people not to have a nice compressor.

My gas compressor around 10cfm with some parts I will need to add to it is around $200 all in. New units with fees were under $600 (store returns etc).

Remember its an auction so there can be some "mines" and if you run a business that is 100% dependent on a compressor you may opt out for double motor brand new unit. However, for "home" use I feel the trade-offs are in buyers favor.

 

[Janger]

Very interesting thoughts Tom. Thank you.

 

[Johnwa]

An ad for this showed up on my Facebook page.
https://passioshop.com/products/high-pressure-washer-sand-wet-sand-blasting-kit

It might work in a pinch but according to some of the YouTube vids it take a higher capacity pressure washer.

 

[Janger]

I've acquired a 5HP compressor and a blast cabinet. I see there are lots of different types of media. I also see there is a horrible lung disease silicosis that can arise from breathing in the dust. If anybody does sandblasting with SAND then you should wear a mask. <EDIT> or anything containing silicon dioxide. Better do your own research here - I think blasting seems benign but is not necessarily so.

What kind of media do I want? Lots of choices even at princess auto. Cheap recycled glass at $12/bag. Copper slag. Glass beads $50. Walnut shells ($40), Aluminium Oxide (expensive, $80/bag). Steel shot. ($100/bag). And there are different grits??? I want to clean up parts with paint on them, remove rust, and also gently even out the finish on machined parts both aluminium and steel. I don't want to damage <EDIT> the finish part.. Any advice?

 

[Tom Kitta]

Well, if you want to be gentle you need thin grit stuff - the heavier the grit the more energy it carries. You can also use thinner nozzle with thinner grit. But thinner grit frequently turns into just cluds of dust.

The metal shot is so expensive b/c it is more or less not destructible - you can re-use it all the time (its metal - easy to separate).

I am not sure what do you mean by not damaging the finish - you mean you want to remove rust and old paint but not pit the surface?

People wear as much respiration and eye/ hand protection as possible no matter the media - its all tons and tons of dust.

I recently used glass - the low grit version is very fine and mostly dust / too gentle to get rid of stubborn paint. I also used the black stuff and it was similar to glass - forgot the type it is. I also have lots of sand now.

 

[Janger]

This is interesting: https://www.mediablast.com/blog/2016/04/28/which-abrasive-to-use/
Seems like glass beads or aluminium oxide have good attributes.

This explains recyclable vs not recyclable media. https://www.mediablast.com/blog/2017/07/06/8-rules-for-recycling-abrasive-in-blast-cabinets/ Lots of media just explodes into dust and contaminates and plugs everything apparently. On the other hand if you can't clean the media then I'm not sure there is any point to worrying about cycling it through the machine more than once anyway...

 

[Tom Kitta]

Wet blasting video. Interesting.

 

[johnnielsen]

I just ordered the wet sand blasting kit. Now I will watch for a suitable pressure washer.

 

[Janger]

https://www.mediablast.com/blog/2017/03/02/abrasive-media-for-sandblasting/

Abrasive media for sandblasting comparison.

 

[Johnwa]

I used the black copper slag. In the pressurized type of blaster it was very aggressive and left a slightly pitted surface (nothing that paint wouldn’t fill). It tended to plug up the feed valve a lot. It worked well in a suction type blaster but that type is less aggressive at the same air pressure..

 

[Tom Kitta]

I am not sure why the comparison is so negative of sand - http://sil.ab.ca/sil4/ that is what I have - if sand was so bad it would not be called... sand blasting.