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DIY Soda / Grit Blaster


Onoff

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DON'T TRY THIS AT HOME!

 

Wanting to blast the mower gearbox (other thread) I'd run out of blast medium. Someone mentioned soda crystal for blasting aluminium on another forum and that I should look up "pop bottle soda blaster". Appetite wetted I went digging for parts. After an ill fated attempt using copper tap connectors I found some heavy wall chromed steel tube. Noted that on the cheap blow gun I have the end screws out and a standard compressor fitting screws in:

 

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The compressor fitting is a pretty tight fit:

 

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I CAD'd up a 2 piece detail to encompass the pipe/compressor fitting gun:

 

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The lid of the bottle gets screwed down through the top half into the lower half and sandwiches the pipe assembly:

 

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The nearly finished article:

 

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Will it work, who knows? Think the barrel calibre might be a bit big and I'll use grit like there's no tomorrow. Also a barrel blockage could see the barrel coming off at speed! 

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Just collected circa 50kg of crushed glass blasting medium:

 

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Had a wander whilst waiting for it to be bagged up. Fascinating (to me anyway):

 

Oak?

 

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Something from Narnia:

 

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Something from Narnia in front of some really big pipes:

 

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And I thought my sliding gate was big:

 

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Bet they've lost count of how many of these done over the years:

 

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  • 2 weeks later...

The home made blasting gun was a failure.

 

Tried the Lidl Parkside sandblasting gun and that kept clogging. Off I went and spent £15 on one of these from eBay:

blast_001.JPG.715deed8596c2ac7eb8737d01d10cb16.JPG

https://www.ebay.co.uk/itm/MARKSMAN...324348&hash=item3d8a3920f8:g:In0AAOSwYP9c0CQi

It comes with no instructions but as far as I can tell the black rubber hose pushes onto the ribbed connector on the blasting gun. The other end goes on the long pipe which you stick into the blasting media.

I did all that, found an airline fitting and screwed that into the bottom of the gun. The metal tube I poked into the big bag of (dry) crushed glass media I got. I drained the compressor of any water.

Started blasting and all was good, cleaning up a strut mount top off the wife's old Pug. Very soon though it was just air, not sand coming out. (Same as happened with the Lidl Parkside gun). The air too appears damp as it darkens the metal you're pointing it at. It doesn't darken it when you start off and it's blasting OK. My very uneducated guess is I need a "moisture trap". Tbh I'm a bit of a compressor virgin. Always borrowed one if I've needed to use my nail guns. Spraying, I've only ever done from rattle cans. By a stroke of right place/right time luck I managed to score an Aldi Workzone 24L compressor for the princely sum of £29.95, new and delivered.

https://www.aldi.co.uk/workzone-2-5hp-air-compressor/p/078920165026500

Coupled it with some cheap air tools from Aldi & Lidl and tbh it's all good so far. (Yet to try the cheapo spray gun).

I think what I need is as I say a moisture trap maybe combined with an "oiler". I have no experience of either. Been looking at something like this:

blast_002.JPG.3a53ce6fe0350bb61f1c7dd030fbda50.JPG

https://www.ebay.co.uk/itm/1-4-BSP-...375798&hash=item3b3a1dfde0:g:wfoAAOSw8oJdlh0D

Specification is: Max Pressure: 220 Psi - Oil Capacity: 130cc - Max Air Flow: 105 Cfm

Compared to others on eBay it appears to have the two "glass" cylinders somewhat better protected by what looks like alloy housings. Some are all "glass" which I doubt would last very long with me!

A question, using an oiler with a blasting gun seems a bit counter intuitive. Yes, it prolongs the tool life but surely it must deposit a film of oil on the workpiece that then needs degreasing?

Any pointers to what's good/bad, what I should look for would be appreciated.

Cheers

Edited by Onoff
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oil is only for tools. Plenty of places run un-oiled air, with the guys putting a drop or two into the end of the tool when plugging in. Or not...

 

Your problem is probably that the air isn't getting a chance to drop the water out in the tank as the tank volume is small. A moisture trap will certainly help. Remember that big setups use a refrigerated dryer.

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36 minutes ago, dpmiller said:

oil is only for tools. Plenty of places run un-oiled air, with the guys putting a drop or two into the end of the tool when plugging in. Or not...

 

Your problem is probably that the air isn't getting a chance to drop the water out in the tank as the tank volume is small. A moisture trap will certainly help. Remember that big setups use a refrigerated dryer.

 

Cheers. Can I get a dual one then and run without oil if blasting, only adding oil if I'm using say the nail gun?

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