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Jamie Valentin
08-07-2018, 1:32 AM
I'm looking to build my own sandblaster and see plenty of ideas online for plywood ones. I don't mind making the top out of plywood, but want the bottom part that serves to "funnel" the abrasive to the bottom via a square chute design to be metal. I want this to ensure easy drainage where the abrasive won't stick to the wood grain. However, I'm not a metal worker. I can cut some diamond shapes out of old washing machine sides with an electric shear, but I'm not sure how to join them. Then I thought of just using something like a range hood because it has the basic shape, but they aren't that deep. Does anyone have an idea for a pre-existing chute or something I can salvage and repurpose? If I could find a giant pyramid toy or some funny plastic dog house I could turn upside down, I'd even go for that.

Thanks in advance for any ideas.

Brian Backner
08-07-2018, 8:04 AM
The most unbelievable blasting cabinet I've ever seen was documented on a website by Dave Propst back in '05. While his website didn't have dimensions given, there was more than enough info available to design and build your own. Unfortunately, I just checked and the site is kaput. Fortunately, for me anyway, I saved the webpages dealing with the build, but I'd have no way to forward or repost them somewhere (even it were legal to do so). However, if you do a web search using "Dave Propst blasting cabinet" a Pinterest page will pop up giving some photos of the thing.

The design of funnels can be quite involved and depends upon the size of the cabinet - and therefore the slope of the sheets - and the material you're blasting, ambient humidity and several other factors to facilitate "flow" of media to the pickup tube. The easiest way around this is to use a vibrator unit. At their simplest this is a small 1/3-1/2 hp motor with an eccentric weight on the shaft to induce vibration. Such beasts are expensive as they need to be designed to take the unbalanced load on a continuous or near continuous basis. There is a company in Cleveland that designs and sells them. They occasionally show up on eBay. Good luck.

Dan Hulbert
08-07-2018, 10:53 AM
I built one many years ago. What I learned was that working with sheet metal is much like working with paper. My suggestion is to mock up your funnel in paper or cardboard and then unfold it to use as a pattern. Scoring the fold lines to guide your folds helps a lot. You may have to add some tabs for the mechanical joints, but a few sheet metal screws and some sealant should give you a working funnel.

Randy Viellenave
08-07-2018, 2:51 PM
You could build it from plywood, then "veneer" it with steel. I read somewhere (don't remember) that somebody used an oscillating tool to induce vibration into a container full of solvent, might be worth looking at for a chute.

John K Jordan
08-07-2018, 4:24 PM
40 years ago I made one by bending sheet metal:

391139 391140

This one was for a bit different purpose, the grit fell in the hopper and I put a nozzle in the bottom aimed to blow a jet of grit straight up. I used it to etch glass (both flat and curved) and clean spark plugs, both held against the foam rubber top. It was easy to make and should work fine for collecting grit for a sand blaster. My metalworking was crude but it didn't need to be pretty. The sheet metal can be thin gauge since little strength is needed. I used stainless steel since I had some on hand.

I made a template first from poster board or something, cut the shape with hand shears, then made the corner bends with a hammer over a piece of wood, if I remember correctly. Sheet metal screws or pop rivets and silicone caulk would hold it together. Making it by bending one piece was easier than trying to join multiple pieces.

JKJ



I'm looking to build my own sandblaster and see plenty of ideas online for plywood ones. I don't mind making the top out of plywood, but want the bottom part that serves to "funnel" the abrasive to the bottom via a square chute design to be metal. I want this to ensure easy drainage where the abrasive won't stick to the wood grain. However, I'm not a metal worker. I can cut some diamond shapes out of old washing machine sides with an electric shear, but I'm not sure how to join them. Then I thought of just using something like a range hood because it has the basic shape, but they aren't that deep. Does anyone have an idea for a pre-existing chute or something I can salvage and repurpose? If I could find a giant pyramid toy or some funny plastic dog house I could turn upside down, I'd even go for that.

Thanks in advance for any ideas.

Carl Hill
08-12-2018, 12:34 AM
I'd go to my local HVAC shop with a sketch and I'll bet they'd do one cheap. With all the CAD stuff today, they could knock out something quick.

Bill Dufour
08-13-2018, 10:49 AM
Note the slope needs to be more then the angle of repose for your blasting media. I would say 45 degrees should cover them all.
Something says plastic traffic cone to me.
Bill D.

Mark Hennebury
08-13-2018, 11:23 PM
I made one a few months back. Plywood, double funnel with steep sides for good flow, blast-gates at the bottom. and a glasstop for natural light. Works fine.

391501 391502391503

Warren Lake
08-14-2018, 2:11 AM
my first one was a ply but it quickly erodes from Rick O'Shea ing sand. I lined it with steel. Looks like Mark is running a pressure blaster there. Make sure you filter your material well I had some mesh filter sand went through every time. Have a restoration friend runs 3 compressors in a sound proof room at 200 PSI. Never a shortage of air in his case and nice you hear nothing other than the sandbalsting noise. He has a full size automotive spray booth set up for just that.

Dan Hulbert
08-20-2018, 3:39 PM
The one John Jordan made was exactly the one I made. Also a little more than 40 years ago. Used mine to etch some glassware for Christmas gifts.

John K Jordan
08-20-2018, 7:03 PM
The one John Jordan made was exactly the one I made. Also a little more than 40 years ago. Used mine to etch some glassware for Christmas gifts.

You must have read the same magazine article I did! Popular Mechanics, perhaps?

I still have mine and use it occasionally. I use it with silicon carbide grit from the auto parts store.

JKJ

Dan Hulbert
08-21-2018, 10:48 AM
I left home shortly after making and using my blaster. I have no idea whatever happened to it. Could well have been Popular Mechanics or Popular Science. My Dad subscribed to both. I've actually been thinking about making another one just for fun.

John K Jordan
08-21-2018, 2:36 PM
I left home shortly after making and using my blaster. I have no idea whatever happened to it. Could well have been Popular Mechanics or Popular Science. My Dad subscribed to both. I've actually been thinking about making another one just for fun.

I also etched a number of flat and curved glass pieces for presents, mostly monograms and such. I don't have even a sample left to show, although I could probably make one easily enough. I wonder how this technique would look on polished wood...

For those interested, you draw a pattern on plain paper to be cut as a stencil. Stick the pattern to the glass with a layer of double-sided masking tape. Cut through the paper and the tape with an xacto knife and remove the stencil elements. Hold the glass tight to the hole in the foam rubber just above the nozzle. The grit bounces off the paper stencil but impacts and "frosts" the harder glass. With sufficiently fine grit this is capable of intricate detail. If I remember correctly, the magazine article showed a copy of the magazine cover etched onto a piece of window glass.

I visited a tombstone company once and it appeared they used the same stencil technique to etch polished stone, but with a heavy self-adhesive vinyl stencil.

JKJ

Bill Dufour
09-02-2018, 3:13 PM
There are sand blasting companies that have a special job of cemetery blasting. they have a portable rig and they go to a cemetery and add the date to a existing headstone after the spouse dies. They have to match up the previous font and spacing.

Derek Meyer
09-06-2018, 5:46 PM
The diagram that John posted looks a lot like a bathroom sink to me. Maybe you could find an old stainless steel sink that would be the right shape to direct the blasting aggregate to the drain, which you could use to collect it.

Warren Lake
09-07-2018, 7:23 PM
thats a good idea but better if it could end up in the pressore blaster in some ways. On the big level was told have a fan system cyclone system and your medium ends up back in the pressure system some how so you dont need to stop and reload.

michael langman
09-30-2018, 11:23 AM
I made a good sized sand blasting box and used aluminum roof flashing for the spout out the bottom. It is thin so it folds nicely into a funnel.
I may have pop riveted 2 pieces of flashing together.

Keith Outten
09-30-2018, 12:16 PM
You might not need a traditional sand blasting cabinet. The pictures below are of a system that I devised to sandblast some large glass signs at Christopher Newport University. My assistant in the first pic is blasting text through a mask using a small pvc box that has a shop vac connected to it to recapture the abrasives. You can move the blast nozzle around on top of the box and/or slide the box in any direction to blast the project. You need to drill holes in the box to adjust the vacuum so you can slide it easily, a valve installed would be an adjustable solution.

I have found out that you don't need the acrylic piece with the large hole. Just cut an extra large piece of acrylic for the blast nozzle and it can slide to the extents of the box. I'm sure that you can adapt this method to something like a 30 gallon trash can or something similar.

We had a contractor bid $60,000 for five of these signs. We did them in house for 5 grand total.

Mike Null
09-30-2018, 5:01 PM
Harbor Freight sells a pretty good one cheap.