mick H | 06/12/2012 18:40:55 |
795 forum posts 34 photos | Has anyone had any success with the cheap shotblasting guns available in the £20 price range? I only have a small compressor...4.5 cfm, 115psi and a 6 litre receiver. From what I have read so far it sounds as if it is probably too low on capacity. I only need to shotblast small parts. Any advice welcome. Mick |
Nicholas Farr | 06/12/2012 19:25:47 |
![]() 3988 forum posts 1799 photos | Hi Mick, I have a cheap one, it's the sort where you stick the suction tube into a bucket of shot (although I used sand in a bag) I had two of these 6 litre things connected into another little receiver through none return valves. It worked well cleaning up the outside of a small worm reducer, which was about 6" x 8" x 4", but both compressors were running all the time more or less, and I felt I had to give them a rest every 20 minutes. Shot blasting does use quite a high volume of air, even with these cheapies. I haven't used it for a long while now. Regards Nick. |
Jeff Dayman | 06/12/2012 19:33:33 |
2356 forum posts 47 photos | Hi Mick, I think you are right about the capacity of your air system being too small. You will need a lot more storage than 6 litres for much sandblasting. I have an 8 cfm / 125 psi compressor with a 90 litre tank. It will allow sandblasting with reasonable force for about 3 minutes with a cheap gun having a .100" dia nozzle. After that the blast is weak and I have to wait for the compressor to catch up. I have added some "air pig" style auxiliary tanks of 50 litres each, which adds to the duration, but really my compressor and tanks are too small for large sandblast jobs. On small parts say 6 x 6 x 6" it's practical but beyond that it really isn't, and I take anything bigger to a local pro sandblasting outfit who have very large diesel powered compressors and a couple of 20 foot high air tanks. Just my $0.02. Your mileage may vary. JD |
Stub Mandrel | 06/12/2012 19:40:59 |
![]() 4318 forum posts 291 photos 1 articles | You can get tiny ones that look like airbrushes. Try chronos. Neil |
HomeUse | 09/12/2012 14:52:12 |
![]() 168 forum posts 12 photos | Hi - If you can "Wet" sand/shot blast and have a pressure washer then try the sand/shot blasting nozzle which is available at many retail outlets - Matchine Mart being one. - Have been using one for quite a time with dry patio sand on small metal parts - make sute you dont blow the item away or cut holes in it as the abrasive power is very high. |
Phil P | 09/12/2012 16:09:59 |
851 forum posts 206 photos | Please stop using sand and get some proper blast media. http://www.silicosis-injury-attorneys.com/pages/sandblasting_risks.html I work for a company that makes these machines, so I do know........ stop using sand !!!!!!! Phil |
John Shepherd | 09/12/2012 16:11:45 |
222 forum posts 7 photos | Mick
I use one of these : Its air requirements are quite modest at 5 cfm and 25L tank capacity but too high for your compressor I think. Whatever you use, keep the compressor as far away from the work as possible to avoid the grit getting into it. Also wear a mask and goggles to stop the grit getting into you. Regards |
mick H | 09/12/2012 16:26:18 |
795 forum posts 34 photos | Thanks for all the advice gents. I do like the look of the axminster product John but I fear that my setup will not have the guts. Having said that, the parts I only need it for paint preparation and the parts are quite small gauge 1 loco stuff...,is it worth a punt do you think ? Neill.....can't find the airbrush on the Chronos site. I shall give them a ring on Monday.
Mick Edited By mick H on 09/12/2012 16:26:42 |
John Shepherd | 09/12/2012 17:03:52 |
222 forum posts 7 photos | Mick I think the one I mentioned might work if you are only doing small parts and not in a hurry. I have used a gun that needed more air than this one on a small compressor in the past, it was not ideal in that I had to do small bursts rather than continious blasting but it did work. Axminster do an airbrush type: http://www.axminster.co.uk/badger-260-mini-sandblaster-prod873608/?searchfor=sand%20blaster but a bit pricy at £50.00ish. I am not a salesman for Axminster honest! |
mick H | 09/12/2012 21:23:42 |
795 forum posts 34 photos | John......had a look at the airbrush.....as you said, a bit pricey for what it is. How does your one operate.....does it suck up the media through a tube or is it contained in the body of the gun? Mick |
Russell Eberhardt | 09/12/2012 21:37:31 |
![]() 2785 forum posts 87 photos |
Posted by Phil P on 09/12/2012 16:09:59:
Please stop using sand and get some proper blast media. http://www.silicosis-injury-attorneys.com/pages/sandblasting_risks.html I work for a company that makes these machines, so I do know........ stop using sand !!!!!!!
This isn't a problem when using wet sandblasting with a pressure washer. Russell. |
John Stevenson | 09/12/2012 22:13:13 |
![]() 5068 forum posts 3 photos | Shove it in a cement mixer with a load of wet sand |
RJW | 09/12/2012 23:24:24 |
343 forum posts 36 photos |
Mick, your rig is nowhere near big enough!
Blasting is Not a fast process either, in fact it's infuriatingly slow at times, and if anything on the surface you're blasting is soft or oily, especially soft paint, it won't get it off, it cushions the grit!
I used my guns in two different situations, One of the biggest annoyances with the hose feed type gun for me, was grit plugging the hose in the hopper, so I'd be forever sticking a thumb over the nozzle to back pressure the plug out! The gun did a cracking job in each case, but the consumption of air (and nozzles) was astronomical, and in some instances when really going for it, consumption outstripped what my compressor could turn out, and it was New, and as grit rapidly wears the (tungsten) nozzles, they get bigger and use more air! Whatever you use to blast, Do make sure you protect your lungs, ears and, eyes especially: grit in any form, dry or wet, is bloody merciless on skin tissue wherever it hits, get it wrong and in your face, it's Very nasty, and the dust even from an accidental lungful will have you coughing for days, any sort of grit is nasty stuff no matter how small the components you're blasting! Whenever you blast media against hard material under pressure, it degrades and creates dust in varying degrees of fineness, and the really fine dust if breathed in, acts in a similar way to diesel particulates, your lungs cannot filter it out and it goes straight into your bloodstream where the body's natural defences attack it with antibodies, so at best, you end up with flu like symptoms and you won't feel good ............trust me, I've been there, fortunately my lungs are still giving 100% oxygen (check up at the quacks last week)!!
If you're going to try blasting some parts, I would strongly recommend you use a cabinet and extractor to contain the dust and, use good ear nd eye protection and at least valve equiped face masks!
If you're not doing much blasting too often, I'd recommend shopping around engineering shops in your area to see if any of them have a cabinet and offer to cross their palms with silver to have them do it for you! Personally, unless you can do it yourself properly equipped, I'd forget it! Just my 2p's worth! John
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Siddley | 09/12/2012 23:57:46 |
![]() 150 forum posts 1 photos | A 20% solution of phosphoric acid will clean and lightly etch steel parts very nicely without the hassle of blasting. If it proves difficult to buy the acid then DEB sell a tile cleaner which is basically diluted phosphoric acid and does the same job ( can't remember the name of it though, sorry )
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mick H | 10/12/2012 07:43:47 |
795 forum posts 34 photos | Once again, thanks for the sound advice gents. I cannot accommodate a larger compressor so I think the alternatives suggested make more sense. Wet blasting, phosphoric acid and sand tumbling all sound practicable as does seeking out a workshop with the right gear. Mick |
RJW | 10/12/2012 09:13:06 |
343 forum posts 36 photos | Mick, if you could give us a better idea of the sort of parts you will need to clean and the material they're made from, it might help folks suggest more appropriate means of cleaning!
Some materials don't take too kindly to acid in any form, or blasting for that matter, Mazak (Monkey metal) for instance! Wet blasting might be ok for bits with some substance, but there's a lot of power in a pressure washer, so if it's a 2" diameter cast iron loco wheel, you'd have to nail it to a plank first, otherwise you could end up fetching it from your neighbour's garden!
I have a jewellery tumbler here, which works great for cleaning and de-burring small items, and can be done wet or dry, but it's a slow process, days in some cases, although this does depend upon the grit used and the finish you need! John. |
Ian S C | 10/12/2012 11:02:08 |
![]() 7468 forum posts 230 photos | The last time I was in a foundry, i noticed that they usedordenary concrete mixers for tumbling their castings. Ian S C |
Siddley | 10/12/2012 13:39:23 |
![]() 150 forum posts 1 photos |
The DEB product is Janitol Altrans - 30% phosphoric acid with a tiny bit of detergent As acids go phosphoric is pretty benign and I don't think there are any safety issues beyond the usual common sense. |
mick H | 10/12/2012 17:50:43 |
795 forum posts 34 photos | Siddley....thanks for that. I have googled it and it seems to be widely available. RJW (John)......I bought Christopher Vine's book, "How not to paint a locomotive" and he recommends sandblasting as excellent preparation for painting. I am building a Gauge 1 "Green Arrow" and the frames are nearly ready for painting. So not a very big job really, as the frames are only about 15" long by 3.5" wide by about 2.5" deep. I don't think that the frames would take kindly to tumbling but it might be effective for other parts. I quite like the idea of the phosphoric acid treatment. Mick |
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