Sandblasting

[n80]

I do not have a sandblaster but my brother-in-law does and he says I can use it any time I want to. So I have a few questions.

Is there a specific medium I need to purchase? I have no idea what he has. He uses it entirely to clean tractor parts. He, of course, has no idea what I should be using for this purpose.

Any tips much appreciated.

What do I need to use to cover parts of the pipe I want to remain smooth?

How much sanding do I need to do before sandblasting?

Do you typically preselect a pipe for sandblasting or do you just sandblast pipes that have flaws in the briar?

Thanks,

George

[KurtHuhn]

I do not have a sandblaster but my brother-in-law does and he says I can use it any time I want to. So I have a few questions.

Is there a specific medium I need to purchase? I have no idea what he has. He uses it entirely to clean tractor parts. He, of course, has no idea what I should be using for this purpose.

He probably has aluminum oxide, it's the least expensive and most "multi purpose" media. There's an outside chance he might have walnut shell or cob media, but it's unlikely.

Generally speaking, a simple sandblast can be done using brown aluminum oxide, or you could opt for white aluminum oxide. For your purposes, either will do fine. Get something with a relatively small mesh size, but not too small (600 grit is far too fine). Also, don't use whatever he has in the sandblaster right now regardless of what it is and what size - the residues from sandblasting tractor parts are not going be desirable on/in your pipe.

This is one area where pipe makers literally spend years doing experimentation with media types and sizes, nozzles, air pressures, sandblaster types, etc. Most are unwilling to divulge that info, because it was expensive to come by. That being said, I know of at least three pipe makers that use three very different methods, with different grits, and even different sandblasters. There's no "magic bullet" for this, so it's up to the maker to figure it out based on what's available.

What do I need to use to cover parts of the pipe I want to remain smooth?

Electrical tape does fantastic job.

How much sanding do I need to do before sandblasting?

220 grit is sufficient. If you leave it at rough grinding stage, 36 or 80 grit, it's possible you'll just be deepening those scratch marks - at least at the beginning.

Do you typically preselect a pipe for sandblasting or do you just sandblast pipes that have flaws in the briar?

Yes.

Sometimes, given the track record of a particular batch of briar, I go into a pipe knowing it's going to be sandblasted, and look for blocks that fit the shape I want to do. Sometimes the briar shows flaws that can't be hidden with stain on a smooth pipe, and it needs to be sandblasted. And sometimes I just get lazy and sandblast things instead of sanding them.

[n80]

Thanks Kurt. Great info.

As far as residue from cleaning tractor parts, is there some sort of cleaning I need to do before starting. And, is the residue from blasting a pipe going to cause any issues with his tractor parts some of which are internals like cranks, gears, etc.

George

[KurtHuhn]

The residue from pipe blasting might not harm the tractor parts - assuming they'll be blown off and washed afterward. The blasting media will do more damage if not removed than the wood dust ever will.

As for cleaning the cabinet before blasting, I think a good wipe down with Simple Green might cover it, but I personally would not make a habit of using the same cabinet that metals are blasted in, or objects that may have petroleum residue on them. With a good cleaning beforehand you can get away with it for personal pipes while you evaluate getting your own setup though.

[caskwith]

The expensive part of a sandblaster is the compressor. If you make a habit of it, talk about buying a small cabinet and using your BIL's compressor with it, then you can keep a clean cabinet with your own media on hand.

[Massis]

The expensive part of a sandblaster is the compressor. If you make a habit of it, talk about buying a small cabinet and using your BIL's compressor with it, then you can keep a clean cabinet with your own media on hand.

I'd agree with Chris here. A cheap cabinet setup can be had for <$150, while the compressor needed to run it decently will set you back 10 times that.

[KurtHuhn]

That's a good idea - then you won't have to worry about cleaning it out, swapping media, contamination, etc. Benchtop blasting cabinets can be transported in the trunk of your average sedan (does anyone besides me buy sedans anymore?).

[n80]

I don't have a sedan! But one would fit in the back of my pick-up.

It is a good idea.....and actually, I've been wanting a large compressor for some time.....

[KurtHuhn]

For compressors, the single most important part of the compressor is its SCFM (sustained cubic feet per minute) rating. Some smaller compressors might look like they will be sufficient, but they post the SCFM at around 40PSI - you will be running at about 90-120 PSI for this application. 15 SCFM at 90 PSI will work fine, mostly. 25 SCFM at 120 PSI is far more comfortable - but that can be a pretty expensive compressor. Capacity of the holding tank is only part of the equation - 80 gallons won't do much if the pumphead can't keep up. I've seen some gasoline engine powered units that will do 200 SCFM at 150 PSI, but only hold about 40 gallons of compressed air.

Mine is 15 SCFM at 90 PSI, so I know that rating works fine - though it pretty much runs constantly during use. You can play with nozzle and jet sizes to get the blaster needs down, which I did, and I tend to run at around 10 SCFM at 90 now. Of course, I made my own jets and nozzles based on airflow calcs from an old engineering textbook, so YMMV.

Also - CHANGE THE OIL! Ask me how I know the demands of sandblasting can ruin a pumphead if you don't maintain it.

On second thought, don't ask - it's pretty self evident.

[n80]

Thanks Kurt. I'm not sure I really _need_ a large compressor for the other things I do (minor automotive, nail guns, etc) but I do get your point about the specs. I'd been looking at large portable compressors but only the more expensive ones will meet the demands of a sandblaster.

[caskwith]

I think a Sedan is what we call a Saloon in the UK. Nobody really buys them because nobody really sells them here, nearly all cars are hatchbacks or SUV style style these days. Personally I prefer an estate, I think you call that a station wagon.

Definitely echo the point on changing the oil often. Oil is cheap, compressors are not. I change the oil in mine every year which is way more often than the manufacturer guidelines.

[LatakiaLover]

Then, there's the thinking man's solution:

https://www.youtube.com/watch?v=OEoAREMHDHM