Home/unit shot blasting setup

[wiganer31]

Hi, I'm looking to put together a shot blasting setup for in my unit, will be looking at building a cabinet to go with it eventually,

Are these off Ebay any good? Item number:
352371734215.

What do people do to get rig of water in the air? I've got a basic water trap atm, would like to build a simple air dryer but still looking for plans with a list of parts.

My compressor isn't huge, not sure what cfm it is but it's a old 115L ingersoll rand, I've used it for loads if air tools and it's been fine along as you let the compressor catch up every now and then

Cheers

 

[henry Kadzielski]

Good morning, my two cents worth. The more air the better, subsequently the bigger the compressor the better. Blasting speed is related to air volume and air pressure. In general blasting, the air pressure in a pressure blasting setup is supposed to be 100psi, at the nozzle. Any psi above 100 improves you blasting efficiency by 1.5% and conversely true any psi lower than 100psi you will drop 1.5% in efficiency. That being said, what is it that you are wanting to blast and what is the the blast media that you will be using. You mention 'shot blasting' does that mean 'steel shot'. If that does you will need that 100 psi at the nozzle and is the system a suction of pressure blast system that you will be using. Speed of blasting will be greatly increased with a pressure blast setup as compared to a suction setup, even with the same air pressure and volume of air used. Moisture, is a big problem and there are several methods of removing it. 1 refrigerated dryer rated for the air flow of your system. 2 Air coolers / filters, these cool the incoming air like a aftercooler then the moisture laiden air is passed through a fine metal mesh where the moisture settles on the mesh, condensers and gets drained out the bottom. 3 desicant dryers. there are others but these are the main three and there are derivatives of these. If your compressor isn't big enough then there will be much time waiting for it to catch up. Also remember recipricating compressors don'y like to be run continiously they will foam up their oil and send it down the air line

 

[Dcal]

There is some kit in the for sale section at the moment that might do your job.

 

[wiganer31]

Good morning, my two cents worth. The more air the better, subsequently the bigger the compressor the better. Blasting speed is related to air volume and air pressure. In general blasting, the air pressure in a pressure blasting setup is supposed to be 100psi, at the nozzle. Any psi above 100 improves you blasting efficiency by 1.5% and conversely true any psi lower than 100psi you will drop 1.5% in efficiency. That being said, what is it that you are wanting to blast and what is the the blast media that you will be using. You mention 'shot blasting' does that mean 'steel shot'. If that does you will need that 100 psi at the nozzle and is the system a suction of pressure blast system that you will be using. Speed of blasting will be greatly increased with a pressure blast setup as compared to a suction setup, even with the same air pressure and volume of air used. Moisture, is a big problem and there are several methods of removing it. 1 refrigerated dryer rated for the air flow of your system. 2 Air coolers / filters, these cool the incoming air like a aftercooler then the moisture laiden air is passed through a fine metal mesh where the moisture settles on the mesh, condensers and gets drained out the bottom. 3 desicant dryers. there are others but these are the main three and there are derivatives of these. If your compressor isn't big enough then there will be much time waiting for it to catch up. Also remember recipricating compressors don'y like to be run continiously they will foam up their oil and send it down the air line

Thanks for the reply, plenty of useful info there. I will mainly be blasting rusty car parts and car floors etc. I'm currently using aluminium shot as it's what a friend can get from work for free, I do have a cheap suction fed setup atm but looking to upgrade to a pressure blasting setup, the suction fed setup dose work ok for a short while then the shot seems to clump up. I've seen a simple air dryer system that I would like to build but I have no idea what fittings and stuff i would need (i find it hard to make sense of simple things like that tbh), its basically 3 bits of scaffold bar, 2 as a cooler and one as a drip leg.
My compressor is a old belt drive system and I've never noticed a problem with the oil coming down the air line.

My thought is get a pressure feed blaster and another water trap, and eventually build a air dryer system and add on a air tank

 

[wiganer31]

There is some kit in the for sale section at the moment that might do your job.

Thanks I will have a look

 

[Brad93]

If you’re doing it on the cheap you may be disappointed.

Try and get a pressure pot cabinet and a extraction system. Otherwise you won’t be able to see a thing.

 

[brightspark]

If you’re doing it on the cheap you may be disappointed.

Try and get a pressure pot cabinet and a extraction system. Otherwise you won’t be able to see a thing.

i have pressure pot and suction gun in mine and use a 4inch woodchip extracta that can pull more air out than the pot can put in

 

[hotponyshoes]

Pretty much as said above, i use 2 big (6" duct maybe?) fans on my cab. One for the dust extraction and one to recycle the shot.
I have a twin v head 2x4hp compressor and it will run it fine providing nobody else is using the air line at the same time. It struggled on the compressors I had before and that was 2 x 3hp connected together.
Dry air is a must or everything just clogs up.
If I want to blast something properly I have to open the drain on the compressor and run it for a few mins, then open the air line at the drop point and the water trap and run it some more before trying to blast. It really needs a proper drier setup though as I can't blast late at night or in the winter.

I thought of running some hoops of copper pipe up and down the walls and sitting them in a bath of cold water at the bottom to get the water to condensate but I think once enough had condonsated it would just start blowing it through in spurts.
The other idea I had was to drill and tap a large alloy block for the air to go into, run the air uphill and have a hole in the air run at the bottom of the block for a collector. Cool the block somehow, either a big fan blowing down some ducting, liquid cooling of some sort or some peliter heat pumps on 2 sides and the top. Another project on the to-do list though!

Edit, I don't know if it would be effective to dry the air on the incoming side rather than the outgoing? Mainly because there would be no pressure involved, I don't know if you could pull the air into the compressor via something like a toilet u bend but filled with silica granules rather than water?
Or dry it with some sort of a/c system? Maybe salvage a car system with 12v control and a mains motor to drive the compressor?

 

[hotponyshoes]

The other thing you need is really really good lighting. Even if your dust extraction is good you will struggle to see, the lights also need to be really well sealed or they will be full of dust and dull within no time.
I think there is some sort of explosion risk with various types of dust which is also a good reason to have sealed lights.
My cabinite also had an earth strap on it but I never.connected it and I haven't exploded yet. Might also have a use for reducing static build up although I don't think I have had any problems with that either.
Good mask is a must, I like the scott vision masks as they have a massive view and no flat surfaces for the dust to sit on. They stick to your face well enough to be wiped off without moving as well.

 

[fizzy]

I have a similar unit - not used a cabinet with it though.
Yes they are air hungry. A Clarke 14cfm compressor will just about cope but bigger is definitely better.
Media needs to be as dry as possible. And use a sieve before filling or it will clog.
They clog anyway all the time - just be patient and when you get a good setting stick with it.

 

[brightspark]

not rubbing it in but with the proper or decent made media regulating valve once set will run all day without adjustment providing the media is uniform ish and dry a secondary tank on the end of the line and a second water separator works perfect on mine if it didn't all I would use is a radiator out of a warm air unit with the 2 fans running over it but fortunately no need

 

[wiganer31]

Cheers for the info guys. It's not just that I want to do it on the cheap, I wont be doing any massive jobs and the bigger jobs I do will be for myself so I dont mind having to wait for the compressor every now and then or emptying the water traps a few times.

This is the DIY system j was looking at on YouTube but I dont know what fittings and valves/pipes I would need

Innk its abit sketchy looking but I kind of like the DIY theam