I picked up a sandblast cabinet at Harbor Freight this week. It's not doing as well as I hoped. I started using glass beads trying to take 2 coats of paint off a headlight switch. Would barely touch it. I switched to aluminum oxide and it did better but took a looong time. I tried to blast a front shackle and glove box door but it wouldn't remove the paint, just kind of roughed it up. I've got a compressor that can keep up and am at 100psi. The book says NOT to use aluminum oxide. Is there a better medium to blast with? The big commercial sandblast company I take stuff to can remove anything in seconds. Are these blast cabinets just very limited in what they can do? I had hoped to take off as many small pieces as will fit in the cabinet and blast and repaint to "detail" this truck.
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Sandblast Cabinet Question
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steelandcanvas
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It just might be you get what you pay for. I bought one from TP Tools and it rips paint and rust off the part in seconds. A little spendy though. I just got it hooked up last month and can't stop bead blasting stuff laying around the shop. It came with a lime/soda glass bead medium, works well just make sure it stays dry. I use a water seperaror before the cabinet and drain the water from my system daily.
jasonjc
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I've got the HF cabinet too, But I've modifid it a lot. I put in better lights and use a TP Tools gun and pickup tube. I also had a hard time getting it to blast. The BIGGEST thing you need is COOL DRY AIR. Do not hook a ruber hose stight from the air compressor to the cabinet. Use a water seperator at the compressor then use steel pipe to get the air to where you need it then another water seperator then to the cabinet. Hot air holds alot more water than cool air. The steel pipe will cool the air and let the 2nd water seperator remove alot more of it than the first one did. I also use a thrid water seperator/pressor regulator on the cabinet. I just blasted all my troop seat parts in just a few hours. Had to cut a hole in the end of the cabinet and make a box too cover it for the long uprights. But it works good for the price. One of those BIG TP Tools cabinets is on my wish list.
nkawtg
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I've had issue with them before, but in my case it wasn't the equipment.....I used a very expensive commercial cabinet and still had issues with some materials I wished to remove. I believe the media and the material you're stripping make the difference. I know glass beads are fairly gentle to the base material, and it doesn't surprise me that it didn't work well against perhaps many layers of durable paint.
My home equipment is an inexpensive suction type that I use regular sifted sand in. It works OK (depending on what material I'm trying to remove), but I would like to get a presurized tank, I've heard they work much better. Do you have different size jets/outlets (can't think of a better term right now) you can try?
My home equipment is an inexpensive suction type that I use regular sifted sand in. It works OK (depending on what material I'm trying to remove), but I would like to get a presurized tank, I've heard they work much better. Do you have different size jets/outlets (can't think of a better term right now) you can try?
Cdub
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I've used Black Beauty fine and had good results, but it still takes some time....
C'dub
C'dub
DanMartin
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I have the HF cabinet and it does pretty well, but I'm using Aluminum Oxide abrasive (yes, the stuff from HF too). I agree with Jasonjc...get all of the water out of the line. I'm using two seperators, and you would be amazed how often I have to empty them. I have one on the compressor (pretty close) with a hard line between them (important) and one on the blasting cabinet. I bet under full load I empty the little one on the cabinet at least once every 10 minutes.
The gun that comes with the HF cabinet isn't the greatest...(it's not the worst either)...I actually use an old (very old) Craftsman one.
Also make sure you have a big enough compressor...that's very important. A small one that is running all the time to keep up will not be enough. If you can't keep at least 100psi to the gun, you're wasting time. I don't know what you have for air, but consider a bigger one that is at least 10cfm at 90psi (which is what I have and would consider "adequate" for home use).
It still takes a while if there is a lot of paint...just be patient. If you are doing really big stuff, consider a scotch-brite wheel on an angle grinder to get the big/thick stuff off first, then into the cabinet for cleanup...that seems to be a good combo for me (less time overall).
The gun that comes with the HF cabinet isn't the greatest...(it's not the worst either)...I actually use an old (very old) Craftsman one.
Also make sure you have a big enough compressor...that's very important. A small one that is running all the time to keep up will not be enough. If you can't keep at least 100psi to the gun, you're wasting time. I don't know what you have for air, but consider a bigger one that is at least 10cfm at 90psi (which is what I have and would consider "adequate" for home use).
It still takes a while if there is a lot of paint...just be patient. If you are doing really big stuff, consider a scotch-brite wheel on an angle grinder to get the big/thick stuff off first, then into the cabinet for cleanup...that seems to be a good combo for me (less time overall).
DanMartin
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...oh, and did you change the tip in the HF blasting gun to the larger one? It comes with a pretty small sized tip mounted in the gun. You should have got a small bag of purple colored tips...change it out for the larger one, that helped me a bunch when I tried the original gun (still ditched it later though for the old reliable).
ygmir
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I don't know much about cabinet blasting, but, I use a pressure pot to carve granite, for my business. I've also cleaned many things for people with this.
Sandblasting is a function of "chipping" the material away......
You need:
inertia: volume of sand, weight/density of same, at speed. This will be a function of oriifice size, air volume and pressure. CFM of your compressor is important in this. Pressure output is mostly the same on compressors 100-140 PSI, but, it's the" CFM at pressure" that will determine the inertia you can deliver with the sand, along with it's weight/density, since, this determines the exit speed of the air/abrasive mix.
cutting ability: with sharper angles on said grains, This causes each grain to chip some of the coating off.
A round glass bead will remove less material per strike, but, make a smoother finish. Sharp, angular media, like "Black Beauty" or a crushed media, will cut faster, and rougher.
and, a perpendicular angle to the surface allows the greatest amount of energy from each grain to be transferred to the coating.
Sometimes, if it's a soft covering, good results can be had by starting a "hole" in the covering and using an accute angle, "peeling" the covering off.
So,
using these principles, you can adjust different factors to change the material removal characteristics.
There are limits on venturi type sandblasters, but, they are nice for smaller, delicate things.
You could probably modify your cabinet to accept the hose/nozzle from a small pressure pot arrangement, so, you could still filter dust and re-use the blasing media, if, you wanted to cut faster.
That's where I'd go if I was trying to get a faster cut.
Sorry for the long post, I sometimes get carried away with details.........
And, of course, these are my experiences, others may have varying results.......
good luck
Sandblasting is a function of "chipping" the material away......
You need:
inertia: volume of sand, weight/density of same, at speed. This will be a function of oriifice size, air volume and pressure. CFM of your compressor is important in this. Pressure output is mostly the same on compressors 100-140 PSI, but, it's the" CFM at pressure" that will determine the inertia you can deliver with the sand, along with it's weight/density, since, this determines the exit speed of the air/abrasive mix.
cutting ability: with sharper angles on said grains, This causes each grain to chip some of the coating off.
A round glass bead will remove less material per strike, but, make a smoother finish. Sharp, angular media, like "Black Beauty" or a crushed media, will cut faster, and rougher.
and, a perpendicular angle to the surface allows the greatest amount of energy from each grain to be transferred to the coating.
Sometimes, if it's a soft covering, good results can be had by starting a "hole" in the covering and using an accute angle, "peeling" the covering off.
So,
using these principles, you can adjust different factors to change the material removal characteristics.
There are limits on venturi type sandblasters, but, they are nice for smaller, delicate things.
You could probably modify your cabinet to accept the hose/nozzle from a small pressure pot arrangement, so, you could still filter dust and re-use the blasing media, if, you wanted to cut faster.
That's where I'd go if I was trying to get a faster cut.
Sorry for the long post, I sometimes get carried away with details.........
And, of course, these are my experiences, others may have varying results.......
good luck
Thanks for the feedback. I went to the TP sight. It looks like the smallest/cheapest cabinet they offer is the same as HF. I saw the upgraded gun they offer for it and am going to order one. I also am going to put in the water separator. I used the tip that came in the gun and then tried the smaller one thinking it would increase velocity. Went back to the larger one but haven't tried the largest. I'm also going to get some sand and try it. Much larger particle than theses beads or oxide. I see how larger tip = more material. The compressor I got is supposed to be 13cfm at 115psi and 14.5cfm at 90 psi. It also just came from HF. Not sure I'm getting that. It was doing OK with the smaller tip but am wondering how it will do with the larger. I was hopeing to do a lot of small stuff in this but it may just be easier to haul it the to commercial blaster. He's going to do the bed and everything we can get to on this truck. I wanted to do engine compartment and cab stuff in this cabinet.
gimpyrobb
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Well, I would tinker with the parts you have and different media before you buy a new gun for it. Having a blast cabinet is WELL worth the time put into setting it up.
jasonjc
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If you get the TP gun get there pick up tube too.
Re: RE: Sandblast Cabinet Question
DO, DO, DO use a full face shield and protective clothing (a welders apron works great). My grinder runs at 10,000 rpm, the chunks of whatever you are brushing are really moving fast when they come off - almost like getting hit by a sandblaster!
I use a wire brush wheel on my angle grinder. DON'T use the cheap HF ones, they only last for about 10 minutes and all the wire bristles are either worn down or broke off. I use a heavy duty knotted brush wheel I bought at a local industrial supply shop. It really rips paint and rust off fast!DanMartin said:
DO, DO, DO use a full face shield and protective clothing (a welders apron works great). My grinder runs at 10,000 rpm, the chunks of whatever you are brushing are really moving fast when they come off - almost like getting hit by a sandblaster!
readyman
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RE: Re: RE: Sandblast Cabinet Question
Aluminum Oxide coarse is sharper/faster for paint, I used a cheap cabinet w/disposable cheap guns. AlumOxide is a better media for parkerizing too, seems to go thru tips faster. Bead blasting doesn't have the same adhesion quality. Blasting makes all the difference in getting paint to stick. Check pickup venting for getting the sand volume up.
Aluminum Oxide coarse is sharper/faster for paint, I used a cheap cabinet w/disposable cheap guns. AlumOxide is a better media for parkerizing too, seems to go thru tips faster. Bead blasting doesn't have the same adhesion quality. Blasting makes all the difference in getting paint to stick. Check pickup venting for getting the sand volume up.
Jones
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RE: Re: RE: Sandblast Cabinet Question
We've got a commercial unit with glass shot and still have varying results.
Cool, DRY air with sufficient pressure by all means. Cleaning the debris seperator screen frequently is a must. Frequent media changes when blasting helps as the media shatters on impact; at first producing new sharp edges but eventually turns into baby powder which doesn't cut at all.
Carbide or ceramic-lined tips are pricey but will outlive a steel tip long enough to make the extra expense worth it.
I've also found that shooting the part straight on will bounce shot back at the viewing window, making changes of the protector sheet frequent enough to be annoying; keep your gun at a slight angle to the work piece. Angling the gun to produce a glancing blow will often work better than straight on too.
Remember too that the harder the coating is the more brittle and easy to chip (blast away) it often is. More resilliant coatings like powder-coat and silicone/RTV absorb the shot's impact and are miserable to try to remove. Luckily though, soft coatings aren't very good at resisting scratching so wire brushing first will remove a lot of the coating and make cleaning up the rest a lot easier.
Lastly, remember that impact produces heat and can even stretch the metal; so when shooting thin-gauge pieces lower the air pressure of hold the gun farther back. Otherwise, you can turn a flat piece into a tin potato chip with little or no effort.
We've got a commercial unit with glass shot and still have varying results.
Cool, DRY air with sufficient pressure by all means. Cleaning the debris seperator screen frequently is a must. Frequent media changes when blasting helps as the media shatters on impact; at first producing new sharp edges but eventually turns into baby powder which doesn't cut at all.
Carbide or ceramic-lined tips are pricey but will outlive a steel tip long enough to make the extra expense worth it.
I've also found that shooting the part straight on will bounce shot back at the viewing window, making changes of the protector sheet frequent enough to be annoying; keep your gun at a slight angle to the work piece. Angling the gun to produce a glancing blow will often work better than straight on too.
Remember too that the harder the coating is the more brittle and easy to chip (blast away) it often is. More resilliant coatings like powder-coat and silicone/RTV absorb the shot's impact and are miserable to try to remove. Luckily though, soft coatings aren't very good at resisting scratching so wire brushing first will remove a lot of the coating and make cleaning up the rest a lot easier.
Lastly, remember that impact produces heat and can even stretch the metal; so when shooting thin-gauge pieces lower the air pressure of hold the gun farther back. Otherwise, you can turn a flat piece into a tin potato chip with little or no effort.
