Hi All
Looking for a bit of advice, I want a quick way of cleaning up donor parts, ideally I'd prefer to buy the gear & be able to do the job onsite - I already have a decent compressor setup.

Now I know very little about the varioius blast cleaning methods, I know I can buy a sand blaster & cabinet quite cheaply, & I'm sure it would get rust & crud off parts, but I'm concerned that no matter how well protected you'll finish up with sand getting in bearings etc which would not be good How about shot blasting, or bead blasting, is this basically the same equipment, or is it something far more expensive? & vapour blasting? what's that exactly? & costs of the above gear?

Guess the Q I'm asking really is, am I better to buy small(ish) cheap(ish) equipment myself or am I better to find someone good locally to farm it out to?

Thanx in advance for any advice!

Edited to add, are any of the cleaning agents, like glass beads for instance reuseable or is it all thrown away?

[Edited on 23/11/10 by russbost]

Also, if its not a high-jack, peoples thought on handheld blast equip such as the below.

http://www.machinemart.co.uk/shop/product/details/sb3-gritblast-gun/path/sandblasting-equipment-and-accessories

Electrolysis has always been popular with people here - realtively easy to set up and very effective at removing rust without the risk of ruining bearings.

We have a DIY made one from an old oil barrel.
You will need a BIG compressor, you need volume.
Obviously don't use sand. We are experimenting with different shot at the minute. But I hear crushed glass is good, but not used it yet.
I've also bought some baking soda to try on carbs and TB's etc.

One rule my dad has given me (he uses pro set ups at work) is that never put in an assembly. You must strip all parts down, ie if you have a brake caliper, it has to be fully stripped or some shot will get lodged in where it shouldn't. No matter how well you think its cleaned after, its not.

Also, its a lot slower process than I thought. I pressumed its would blast away all crud in seconds, but when using it you have to work quite slow over the parts. A small exh mani took me a good half hour to do a 'quick' blast over.
But the results are pretty good.

You can use a lot of different media in for instance, an ebay sand blast cabinet. Some are more aggressive than others but the net effect for our purposes is about the same.

I have used lead shot, iron oxide sand and bead.

Lead shot took everything off very quickly and left the parts looking lead coated, if you know what I mean. It didn't change the surface finish too much and the parts are now some of the toughest I've ever painted (you need a flap disc in a grinder to remove plastikote off them!)

Iron, well wow. It took everything off and some of the metal. It came out feeling like 60 grit sandpaper and I had to de-nib the parts which took hours. Super pain in the butt, and the finish isn't suitable for paint untill you have rubbed it down for a long time.

Beads: That worked well, did a pinto head with this and in all fairness it looked new. It didn't mark the cam bearings despite them being left in there (albeit they weren't aimed at) so it is quite an unaggressive media. The finish was brilliant and ready for paint and it didn't change the surface finish of the metal at all.

Sand, well normal grit if you will, the stuff that feels like sand. I find this to be very tiresome. I recently tried to get some powdercoat off with it and it was taking all day. I ended up hitting it with a knot wheel then using the sand to even out the surface finish. However this stuff is good for say, frosting perspex parts, or designs onto perspex/metal. You can mask up logos and blast them into parts you make which looks really cool when it's done. However it's not enough to take rust off. It can't even budge the surface rust that was on my front grille without a few passes.

On balance I'd say the lead stuff was the best overall. I did some alloy wheels though in that cabinet and they did come out a little peened looking. But for cleaning up parts such as suspension arms, hubs, blocks, etc it was ace. For alloy heads, rocker covers, brackets etc I'd be inclined to use one of the roughest sand type grits available.


As for it getting everywhere. It just does, no matter what the media it will get everywhere, behind seals, in oilways, in every thread etc etc. It's a potch, but as with everything it's a time vs finish balance. Given how quickly you can turn a part to bare metal, an hour cleaning a head for instance, and running taps up the threads etc to clean it out seems worth it to me.

If you have enough to do in order to warrant buying a machine I'd get one myself as they are very handy. They do take up a bit of room though and are messy as the dust goes everywhere despite the cabs being sealed. A garage I worked in bought a blast cabinet that was capable of fitting 2 alloys at a time in from a liquidation auction along with some other bits. It was floor mount with a side door and foot pedal operation. That was the absolute business. The nozzle was about 1/2" diameter and like the end of a hose pipe which made it very pleasant to use.

I'd recommend one with a pedal if you do buy one as it quickly becomes very annoying to have to squeeze the trigger and jet the shot all around the part. You end up with hand cramp in about 5 mins.


That's my 5p worth Russ, I'm no professional shot blaster though so feel free to disregard any of the above!

ATB
Stott

Someone on here messed up a diff by shot blasting the complete assembley, I belive he had to have it professionally rebuilt

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Originally posted by balidey
Also, its a lot slower process than I thought. I pressumed its would blast away all crud in seconds, but when using it you have to work quite slow over the parts. A small exh mani took me a good half hour to do a 'quick' blast over.
But the results are pretty good.

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I have used alluminium oxide and glass bead in various grades. Alluminium oxide is very aggressive as it has sharp edges and leaves the surface rough, perfect for a paint finish. Glass bead works more on an inpact principle rather than cutting as it is like microscopic marbles. Great on alloy if you also want a decorative finish and looks good if you mask the surface with, say brown packaging tape or sticky back plastic, cut it away to expose the surface then blast it. I did an alloy wheel boss for my JC Midge with a logo years ago and once its there it aint gona go anywhere. I have also done carbs but masked the mating surfaces and stripped down completely. As has been said, compressor capacity is critical. There are loads of other abrasive media, crushed walnuts, cork (believe it or not) plastic bead etc.

here is what i would advice you to do enjoy my post on the scotish vag forum on blasting

i have 3 diferent blasters
1 for a jetwash (5/10)
1 for a compressor (8/10)
1 homemade soda blaster that works the best.( 10/10)
enjoy

http://www.scottishvag.net/phpBB3/viewtopic.php?f=101&t=37527

Used the bead blaster at work for a lot of parts, fantastic! Sierra uprights wishbones ect, all steel great surface for painting onto. Even did the uprights WITH the bearings in you can do it BUT YOU MUST MASK THE AREAS VERY CAREFULLY, including the tapers ect (a box of rubber bungs are what you need, leave them it for painting as well). I successfully masked the bearings with a lot of string wound around the axle covering the area, then covered this in many layers of tape. Id doing this professionally I would suggest re-building with new bearings as you might get grit in! After 1.5K my bearings are find so it is possible, but on a customers car/parts this is asking for trouble..

Anything that could not be bead blasted (to big not/not time to take into work) was done the best I could (electrolysis wire brush, emery, degreased etc) then etch primed to make sure the paint stuck, as worked really well. Only thing I regret is not using a exterior gloss top coat as this is more chip resistant than the chassis black I have.

Dan

[Edited on 23/11/10 by Bluemoon]

[Edited on 23/11/10 by Bluemoon]

I have the smaller Clarke blasting cabinet (the one that's a glove box) and use their aluminium oxide grit. To feed it I use two 3hp compressors (I don't have anything other than standard 240V, single phase domestic sockets in the garage) which I would say is the bare minimum. For cleaning up stuff, I think it's brilliant and much easier than using wire brushes although I've never tried the electrolysis approach. The only thing I would say is that the window gets obscured very easily and it soon becomes almost impossible to see what you're blasting. So I either use "feel" to gauge where I'm blasting or do it with the lid open and lose a load of the grit.

do the little Clarke ones not have a vacuum cleaner attachment?
We built one into ours behing a baffle and it keeps the air inside fairly clear of dust.

isn't there something about using crushed walnut shell as a blast media? apparently its quite good. think it was on american hotrod i saw it?

quote:

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Originally posted by alexg1965
The only thing I would say is that the window gets obscured very easily

.... do it with the lid open and lose a load of the grit.

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crushed walnut shell is great for polishing brass, I use it in a vibratory cleaner to clean all my brass gun cartridges before reloading them.

vapour blasting leaves a nice finish on ally.

and as mentioned above I regularly get vinyl logos etc cut at local sign shop, then use them as templates to frost perspex and brass etc

also use the sandblast cabinet to give a matt non reflective surface on red acrylic etc when I have made custom tail lights for bikes, it just adds to the overall effect

Thanx for all the info so far. Hadn't realised they were so energy consuming re the compressor, I have a 3HP with a big tank & won't want to do a lot at a time, but still sounds like it's likely to struggle.
One thing I'm not clear on, if I buy something like a Clarke or Sealey for about £250 is it going to handle stuff like glass beads & lead shot or do you have a different gun for that?

quote:

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Originally posted by russbost
One thing I'm not clear on, if I buy something like a Clarke or Sealey for about £250 is it going to handle stuff like glass beads & lead shot or do you have a different gun for that?

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Personally, I wouldnt be worrying about bearings at all. There isnt a chance Id be taking donor parts off a car and re-using service items with an unknown life.

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Heres my set up. you can use a 3hp compresser mine is a clarke 14cfm with 50 litre receiver. my dad made the cabinet for his business many years ago. He had a look at the Gyson cabinets but he thought they were crap and very expensive and after seeing one I agree! The secret to using a small compressor is to directly tap off the tank rather than using the built in regulator which is quite restrictive. I removed the 3/4 bsp plug and fitted the required valves and connectors but the main difference is the blast cabinet is fed with 1 inch diameter hose to a bigger regulator then foot pedal. The blast nozzle is about 5/8 and will go at 90 PSI constantly using paving sand to good effect. I use a wood vac to keep the cabinet clean (4inch pipe)

I use a clarke cabinet that we have then modified larger, my own home made lid, new 6mm thick acrylic top, with tear off 1mm thick clear inside, so that when it becomes misty and obscured, you just tear that out and stick a new bit in

mines run at 100psi and the compressor is rated 44cfm at 100psi, plus a 420l tank runs happily no problems

Thanx for all the info guys!