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Post by rodders on Feb 3, 2014 8:29:52 GMT
This is very interesting! Have an old redundant paint spray gun that seems to have (after watching the numerous utube vids) a convertible configuration?? Just replace the feed bowl with a vented hose into the plastic bucket and open the jet nozzle progressively. The secondary (dry) air feed directly into the feed tank to provide positive pressure and agitation also seems very sensible.
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Post by Roger on Feb 3, 2014 8:45:21 GMT
This is very interesting! Have an old redundant paint spray gun that seems to have (after watching the numerous utube vids) a convertible configuration?? Just replace the feed bowl with a vented hose into the plastic bucket and open the jet nozzle progressively. The secondary (dry) air feed directly into the feed tank to provide positive pressure and agitation also seems very sensible.
The YouTube videos just show a hose picking up from a bucket of Soda with a crude arrangement with holes in the side to allow it to be drawn in without blocking. The gun can be very crude indeed by the look of some of the arrangements that work. I'm certain that you can do something with your gun. One thing I was concerned with was making sure that the nozzle arrangement created a vacuum to draw up the Soda. I think the outer nozzle has to be bigger than the inner 'lance' else that won't happen. I may need to make the outer one bigger on mine. I drew is small to start rather than bigger so I can open it up. That's easier to do than the other way round! I'm not convinced about the positive pressure, I'm hoping that won't be necessary. Roger
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Post by rodders on Feb 4, 2014 14:28:36 GMT
Nearly there with soda blaster. Next question is - Where is the cheapest source of bicarb??
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Post by Roger on Feb 4, 2014 17:56:52 GMT
Nearly there with soda blaster. Next question is - Where is the cheapest source of bicarb?? Good question, I haven't even looked yet. My first port of call as always will be eBay. Roger
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Post by rodders on Feb 5, 2014 8:06:43 GMT
Having only a small hobby compressor, 2HP 8 bar max. I am guessing that, for small model work, a reduced dia. delivery hose would be better for the low available c.f.m? I am proposing to try 1/4" (because I have some.)and this vaguely matches the vent tube dia. that I will put into the reservoir tub in tandem with it. Ref. arrow shaft on utube.
Aside - The best price found so far for soda is £17 ish for 25Kg.
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Post by Roger on Feb 5, 2014 9:06:41 GMT
Having only a small hobby compressor, 2HP 8 bar max. I am guessing that, for small model work, a reduced dia. delivery hose would be better for the low available c.f.m? I am proposing to try 1/4" (because I have some.)and this vaguely matches the vent tube dia. that I will put into the reservoir tub in tandem with it. Ref. arrow shaft on utube.
Aside - The best price found so far for soda is £17 ish for 25Kg. I have to put my hand up and admit that I have no idea about delivery tube size and air consumption until I try it. I'm imagining that the effectiveness of the process is going to be largely dependent on getting a really high velocity into the soda particles. Having too much being drawn into the chamber may make it less effective but only experiment will tell. I can see that there's an ultra coarse grade one in 25kg bags for £19.20+£10 P&P, but that has particle size of 285microns which seems like billiard balls to me. I was imagining something with half that size. Some of the media seems very expensive. Have you got a link to the one you found? Roger
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Post by Roger on Feb 6, 2014 8:51:51 GMT
Here is the link to a UK source of media where you can but fine and coarse grade soda, one being 100 micron and the other 285 micron particle size. Looking at more videos, I think I'm going to leave plenty of material on the outside of the nozzle cone, because the hole in it may well need to be made larger. The DIY blasters seem to be mostly showing the use of soda from a supermarket, and that would appear to be too fine.
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Post by rodders on Feb 6, 2014 14:27:13 GMT
Roger I believe I misled everyone with the media price. Now purchased at £24 including postage. (125 microns.) The other offer had £10 delivery charge attached. Apologies!
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Post by Roger on Feb 6, 2014 16:37:03 GMT
Roger I believe I misled everyone with the media price. Now purchased at £24 including postage. (125 microns.) The other offer had £10 delivery charge attached. Apologies! That's a good price if it's for 25Kg, where did you find that then? Roger
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Post by rodders on Feb 7, 2014 8:27:46 GMT
Roger Fleabay - Bicarbonate of Soda 25kg - Sodium Bicarbonate Bath Bombs ... (281257644114)
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Post by Roger on Feb 7, 2014 8:51:04 GMT
Thanks Rodders, I've just looked that up, but the particle size doesn't look like 125 microns. The picture shows that they're supplying the Granular product, and the spec sheet says that's 250 microns with an average median size of 185 microns. Doubtless is will work just fine. I've also found this source on ebay 200776883653 and they have smaller pack sizes but they don't mention the particle size. I've just asked the question so hopefully they will be able to tell me. 25Kg is an awful lot so I'd rather buy a 10kg bag since it's just an experiment. Roger
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Post by rodders on Feb 12, 2014 13:43:03 GMT
Roger Bicarb is delivered and looks to be 125 micron "ish" to me. Will let you know how it performs later.
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Post by Roger on Feb 12, 2014 22:23:41 GMT
Roger Bicarb is delivered and looks to be 125 micron "ish" to me. Will let you know how it performs later. Excellent, yes, I'd very much like to know. Mine's ready for a test when I hear from you. Roger
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