Shot Blasting & Compressors

[Andy W]

Hey all,

I'm tying myself up in knots on the www & starting from a point of zero knowledge so here I am, throwing myself at your mercy & combined experience!

I want to clean up a load of parts & a shot blast cabinet seems the way to go BUT I have no compressor or cabinet....
Cabinets seem simple & cheap enough (starting at £65 on eBay) but the world of compressors seems more expensive & complicated.

Any advice as to what I should look for is appreciated (I am on a DIY budget btw),
also,
If any one in or near Devon has a set-up for sale, then let me know.

Cheers,
Andy.

[RobThomas]

I've got one and although useful for some things, it isn't as powerful as an industrial kit. Boat yards use them so if you are near the coast you might find someone who already has the kit and will do the work for you. If you want to do it all at home then a big tank (150 litre?) and a big pump (maybe 15 cfm F.A.D.?) will run everything you need. If the tank is too small it will force you to pause often, likewise a small pump/motor.

I also fitted a big vacuum cleaner thingy to suck all the air back out of the cabinet after it was blown in so that it didn't pop the glazing out. Lots of nasty dust so you need some DECENT face masks with filtering. Starts to become costly. If you get some of that grit blown round the workshop and then into an engine...

[bmcecosse]

Shot blasting needs a huge compressor and very good extraction equipment to take away the dust created. It's really an industrial process and not at all suitable for DIY. You may be considering 'sand' blasting - although note that 'sand' is not permitted (high risk of silicosis) - the usual media is glass beads..hence th correct title of 'Bead Blasting'. Smaller compressor, smaller extraction equipment and a smaller cabinet. Still seems like a hammer to crack an egg....there must be easier ways to clean up whatever it is you are considering. There is a simple electrolytic process that strips off 'rust' if that's the problem - can't remember the details but it's been discussed on here often enough - I'm sure someone will be along with the details very soon!

[panky]

If it's de-rusting fairly small items, and you're in no rush, try immersing the items in a mixture of molasses and water - it really does work No good for removing paint or grease though.

[bmcecosse]

For 'molasses' - is Black Treacle good enough ?

[panky]

Not sure but I've got two tins of it in the garage waiting to try. Found them at the back of the cupboard and well out of date so should be nicely fermenting
I think I'll do a test piece, I'll get on it tomorrow.

[philthehill]

Thank goodness for Lockerley treacle mines is what I say.
My small Machine Mart blast cabinet is an absolute necessary for me. Run from a 13cuft/min compressor with 50ltr tank. The blast cabinet has had additional external filters fitted to reduce the possibility of dust entering the atmosphere.
Phil

[ianmack]

Ah, fame at last for the legendary Lockerley treacle mines! All those vast untapped reserves just waiting to receive dunked Morris parts.

[bmcecosse]

Nobody coming up with the electrolytic method? As I remember it was very simple 'bucket' chemistry.....

[moggiethouable]

http://csblasting-1649997.calls.net/sho ... 2900706102
I would sub contract it.

[ian.mcdougall]

I used the electrolytic setup to de-rust some lathe parts, it works but for heavy rust it may have to be wire brushed and dunked again the sacrificial piece of steel that the rust attaches to looks disgusting and the electrolite gets murky, bought my kits through Frost, came with all to set up and go.Restricted to the size of the bucket, so not very large pieces can be done.

[irmscher]

Soda blasting is a great way and it protects the metal from flash rusting

[philthehill]

Some photos for Perkinsp3 of my post blast cabinet filter set up.
The complete works - the vacuum cleaner is fitted with a HEPA filter.
[frame][/frame]
Additional paper filter fitted over HEPA filter[frame][/frame]
Bayonet fitting utilised from 2nd ash can extractor fitted to cabinet[frame][/frame]

[BLOWNMM]

Rust removal
Here you go - have used this method on many occasions with excellent results.
http://www.rickswoodshopcreations.com/m ... emoval.htm

[perkinsp3]

Some photos for Perkinsp3 of my post blast cabinet filter set up.
The complete works - the vacuum cleaner is fitted with a HEPA filter.
Additional paper filter fitted over HEPA filter
Bayonet fitting utilised from 2nd ash can extractor fitted to cabinet[

Thanks for the pictures Phil, all makes sense.
Noticed the Workzone boxes, hope Aldi have more this year.
Thanks again
Pete

[Andy W]

Thanks for all the advice folks,
I got a bit carried away & decided to go for it..!

I do not know how to put 2 x pics in one post so here's the cabinet I bought...


[frame][/frame]

[Andy W]

...And here's the compressor..![frame][/frame]

[RobThomas]

Looks good. If you have the box in the garage I suggest you pull it outside when you use it. Very, VERY fine dust comes out of the corners and will get into everything, including lungs. Glass beads are good for soft items and grit for steel bits but both will quickly ruin the glazing panel with masses of scratches. A Vacuum like the one above will help to keep the box sealed by sucking the lid closed (Ebay/Gumtree/Lidl cheapo is fine)
Keep the air intake for the compressor away from the dust, keep the grit/glass as dry as humanly possible and drain off the water that WILL get trapped in the bottom of the big tank whenever you use it or it WILL rust out.
The lamp in that box will last a while but with so much dust you'll struggle to see what you are blasting quite soon after you start so having it outside helps. The 'gloves' are held on by friction and a cheap jubilee clip so if the vacuum cleaner is powerful it will keep sucking the gloves right off. A major PITA to get them back on again! A dab of glue or silicone sealant on day one might help.

Been there, done that!

Good luck.

Rob

[Andy W]

Inspired by philthehill's pictures...my Heath Robinson air extraction effort uses a trimmed & glued Henry vacuum cleaner fitting with the Henry hose leading to my garage vacuum cleaner!
A bit of a bodge up but it works! [frame][/frame]

[GBond]

Sandblasting is one of those things you never think you need but when you have it you'll end up using it all the time.

Few tips:

Always remove all grease and oil from parts, you might be tempted not to do it but that'll gunk up the sand (or whatever media you're using) and it'll be a bigger pain to clean the pipes later.

You'll probably need to change the window after every 5-10 hours of blasting if you intend to be able to look at what you're doing.

Get a bunch of strong magnets, speaker magnets are great, these will help to keep smaller parts from flying away and will save your left glove. I even do screws and fasteners frequently and they come out great! (Will need some sort of treatment after, nickel or tin plating are great options)

If you can fit a light inside the cabinet, that will also help you a lot.