Sand blasting questions.

Hello, im having some difficulty selecting a beed blasting or sand blasting set up. I have old propane tanks i cut up and recycle to make into little stoves. I have one quality issue left to weed out. Rust. I cannot seem to get every nook and crany with wire wheel, or power sanding, and even some micro pockets remain that promote rusting underneath the coats of paint i put on. I was told that sand blasting or beed blasting would be the next most thorough, fastest, and economical method for doing this correct?
If so, i wanted to know what you all would suggest. I thought that sand blasting would be nice except that i would probably construct a small outhouse size booth with a blower and air filter attached, to contain the dust. Either that, or i might construct a smaller booth just to fit the stove body's into, and find a way to attach the hose from a sand blaster. I think a sand blaster would be nice because its portable and versital, so i am leaning toward that, but would definately need to build some confinement for the dust.
These will be a constant production type item, so this is a long term thing, but i also dont want to buy more than what is needed for this job.

So, given that that would work, what would be the best size compressor and sand blaster that would do this job, and do it fairly quickly and efficiently. I would like to sand blast each tank outside only, and be done with it well within 20 mins.. Am i looking for CFM, or PSI, or both. What size tank would give me that kind of duration and power?

Here is a local pickup only, ebay item i was looking at, would this size of compressor be enough?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230194770552&ssPageName=ADME:B:WNA:US:1123

Thanks.

Compressor Size for Sandblating

You will need a minimum of 10 hp electric to do the job with any kind of speed. Otherwise you might as well be doing it with an eraser. I would suggest a gas or small diesel compressor with a minimum of 40-50 CFM. 100 CFM would be better. Realisticaly, you can run a bead blaster with about 12 CFM (5 hp electric) for a couple of minutes before the pressure gets too low to continue. After a few minutes the compressor will be back up to pressure and you can blast for a couple of minutes again. Pretty miserable, all in all. In addition, the fewer CFM that you have to work with the smaller the nozzle has to be and the smaller area gets cleaned per minute. There is no free lunch.

I see. I think i need heavy flow too. Not just for the rust removal, but making a nice surface for the paint.

sand blasting

check on a powdercoater in your area might give you price on cleaning and coating much faster and cleaner

if your product will fit within a large sandblast cabinet, that would be the easiset way to get started and still contain the mess. Based on your stated interest, you need one with a gun set up to optimize use with a 10HP or larger compressor. Remember when sizing a cabinet that not only the product has to fit, but it has to be easy to turn it, and have plenty of space all around to manipulate the gun. (the cabinet needs to be a whole lot bigger than the the standard items intended to blast)

If you are truly into steady mass production, it might be better to sub out the blasting and painting as already mentioned.

Or there are automated facilities that can be tailored ot your application.

http://www.wheelabratorgroup.com/

http://www.pangborn.com/ (there are some videos of wheelabrators on this one)

This type of equipment tends to bring pennies at auction because very few need it or know what it is. (Also tends to be well worn, and *big*). But I have seen smaller self contained set ups.

Also google "silicosis" just so you know, though you sound like you are planning to take good precautions.

smt

Check this place:
www.tptools.com

I have one of their 960 models & it kicks butt, They also sell compressors with blasters as a compete set up.

Yeah, ill check into farming it out, and weigh options. Building it myself and doing the work myself is more in my way of thinking, but it depends on timing and funds right now.
I must say, ive been around beed blast cabinets and used them, but honestly havent been around a sand blaster like the one lower on this page.
http://www.sundanceglass.com/sandblasting.htm

This seams closer to what i had in mind though. I was thinking i could put it all together for under $900, but not sure yet.
http://www.aircompressorsdirect.com/catalog/product_info.php?products_id=555

Would 18 cfm be tolerable? And so this means, 90psi needed for that cfm, if nozzle is opened up... i think.
What doesnt make sense, is that on the next page, there one for only 6 cfm, and it costs a lot more. Typo maybe?

Im leaning towards this portable sandblaster instead of the booth. It would be nice to be able to go mobile with it on other odd projects. At the same time, i could make my own small walk-in cabinet or otherwise, blocked off area.

As for the compressor, i could almost see having one that could deliver enough power for 5 to 10 mins at a time, and be ok with that too.

Thanks for the great suggestions so far.

I have a home-made cabinet that is about the size of one RickWG refers to. In fact it is made with TP Tools parts from their plans. I supply it with a 5HP/80 gallon compressor and it is not near as bad as Avanti says. Usually my hand gets tired or I have to move the part before the pressure drops enough to be ineffective. I'd love to have a 100 CFM compressor, but it would be overkill for my purposes. It might not be overkill for you, if you're really cranking them out and can recover the cost. If your only doing a couple a week, you could get by with less.
I borrowed a pressure tank several years ago to blast some large castings and if you don't know it makes a heckuva mess. Certainly don't want to use it within 50 feet of your wifes car.

First off, 18 cfm isn't even close to what you need. I've done some home blasting, and you will only be able
to blast about 1/4 of the time with 18 cfm. For sandblasting, think air compressor on trailer.

Speaking of which, I don't live real near you (up in the Seattle area) but it is thinkable to drive up here and back
to get a machine. And I have one for you! It's a solid Quincy air compressor pump driven by a Wisconsin 18 hp motor, all on a neat little trailer. I'm using it on a job right now to run a big plasma cutter, but in about 2 weeks when I'm done, it will be available. At $750, it is a ton of air for the money. Let me know if you're interested.

Grant Erwin
Kirkland, Washington

18cfm is not half enough air for your described use. It is marginal for hobby type stuff, and is like someone else said, about like working with a pencil eraser. If you are doing this as a paying propostion, money is lost down the drain every extra minute standing in front of the blast cabinet.

Rickwmg, TPS does provide some options, but he would burn up that vacuum cleaner based universal motor dust collector in a few weeks with the work he says he wants to do, and 18ga sheet metal is inadequate for a cabinet for industrial use. Some of their self described "commercial" units might be a good starter set up, decent collectors with real motors, and 14ga cabinet metal. Suggest one with a door on both ends for ease of processing load, unload. Also, in a pinch you can run longer stuff straight through or build a box on one end for extended lenght objects. Also, for steady use, he might be better off with an outdoor cyclone for the volumn and for the fact that they, too are cheaper than the supplied self contained dust collector units.

I still think he ought to find a self contained wheelabrator, but maybe production is not quite as heavy as stated.

smt

Booster,

How big are these tanks you are working with? Can you post a picure of you finished product?

Tom

Alright, so to small at 18cfm. I guess i need hands on with these things for perspective. Im taking this all in still. I was hoping that my budget would allow for this amount of work/per hour result, but it looks like im right on the threashold of being able to buy what is needed.
metalmagpie. Your offer has my interest. Do you have more specs. or even a picture of what you have there? I'm trying to find someone to manufacture my items still, and am getting dicked around by american companies. Im trying my best to keep this in the USA, but if the American companies don't want to do business, i will be forced to look to the next closest country for a fabricator. If the domestic manufacturers come through for me, i may be interested in your compressor within a month to 3 months. If they dont, it may be 3 to 6 months before ill be looking for something like that.

Thanks again everyone!

Flathead. I can't show the complete design, because there is still design protection issues being played out. The tanks are your typical 30lb and 40lb propane tanks. There are a few handcrafted and blacksmithed items made and welded to it, so the 30lb tanks are typically 24"OL by 12"DIA. And the the 40lb tanks would be 32"OL by 12"DIA, but they both have some small delicate extensions on one end, adding 21"Length to both of them. 65"X65"X20" might be a cabinet size i would need for the largest of my product line. That is too big for most cabinets in my price range. That is why i thought a sand blaster would be perfect. I could either do them outside with beach sand media, or construct a booth or some type of containment for the sandblaster to be mated with.

Am i missing something here, or is there a logical reason that there isnt a combination blast cabinet/portable sand blaster type unit on the market?

Me and a friend were considering building a type of tumbler for this thing, but it would be hard to design something that wouldnt damage some of the attachments, and im not sure tumbling would realy get the job done as well as i need it on this item. I shit canned that idea so far.

please post a picture of the compressor/trailer. Here are the four I have, you can never have enough air! Shawn

Okay are the TP tools blasting cabinet a good deal? I need to buy something, not for production work. A couple of hours use a week max. Shawn

A friend with a fab shop says forget sand. Use Black Beauty, which is a coal slag media. Much sharper, works faster.

Shawn, in one of my previous posts i was not trying to "run down" TPS. They have figured out a combination of cabinet, gun, and price point for just about every potential user of abrasive blast equipment from the hobbyist to the professional/light industrial. They support the equipment with spare parts and just about any knick-knack impulse buy it might occur to you to "need" this month. My point was merely to get the set up that is appropriate to the user's needs. They have a lot of ways to mix & match & one of them might be you.

The lower price units sold by TPS give a lot of capacity for the $, but are probably not appropriate to someone who is going to be using it several hours a day all week every week such as the OP. For you, me, the average light commercial user and corner garage, they could be ideal.

There are several ways to keep the price down: using thick metal for the cabinets costs more for material, bending & fab costs, and shipping. So the lower price cabinets are made of 20 - 22ga which is fast & easy to work with. The mid range is 18ga. Their higher price cabinets are 14 ga. All do seem to have 11 ga doors.

A *good* dust collector is essential for convenient blast cabinet operation. The lower price packages include basically a re-configured vacuum cleaner with the typical universal vacuum cleaner motor. That will work fine. But estimate for yourself how many hours you would leave a shop vac running wide open with the motor covered and feeding it sand. I fyou only blast a few dozen hours a year, that will serve well enough. For blasting several dozen hours every week, it might be prudent to investigate a set up with a real motor, outside the blower housing. For full on regular use, I would get something like a 2 - 5 HP Torit cyclone at auction for not much money and run that. Over kill, but it will last forever and they are very cheap. If you are in a residential area, you may have to bag the output or run it under water.

The lower priced units have lower capacity guns, which are going to be ideal for a 5HP or less compressor. For "production, a gun that can be configured for higher air flow will be a better choice.

The rest of the choices boil down to cabinet size & configuration, lighting, and number of doors. The higher price point set ups tend to have more and better spare consumables, and more "starter" abrasive, but that may or may not be a better deal

You can probably find one that meets your needs. Just go into it comparing the features needed.

I bought a TIPS pressure pot blaster maybe 20 years ago and am still happy with it for my needs. More recently since they are now TPS, got one of their heavier cabinets. So I'm not running them down.

Booster: In response to your Q, I believe Trinco makes pressure pot cabinets as one option. So to some extent you could blast in or out of the cabinet. I considered one since my wife blasts rocks (sand carves) and a syphon is not effective for that. But ultimately decided I could adapt my pressure pot to the syphon cabinet if necessary. Trinco is a little pricier, size for size, but again, they may suit a certain market segments needs better.
Cabinet blasters usually use syphon guns and continuously recycle the media.
"Outdoor" blasters are usually pressure pot style where you fill the pot, and blast until it runs out, then re-fill. Some people blast in sheds and due recycle the media by shoveling it back up, sifting, and refilling the pot. A pressure pot will get more effect for the same amount of air. Mainly due to the length of time the abrasive is acted on by the airstream. In a syphon, the sand comes up a tube at a relatively low velocity, and then is accelerated a very short distance in the nozzle. In a pressure pot, the air is accelerating the abrasive the whole way down the hoze, it's traveling near optimum velocity by the time it hits the nozzle. Sort of the same effect of shooting a 22 round out of a snub nose pistol vs a rifle.

smt

Thanks smt. That does help narrow it down. I'll go look up that pressure pot cabinet combo. Thats sound a lot like what im needing.

Shawn Ghormley said:

Okay are the TP tools blasting cabinet a good deal? I need to buy something, not for production work. A couple of hours use a week max. Shawn

Click to expand...

That's about the most use mine gets & I have it fed by a 6hp Devilbis Pro4000 2 stage/60gal compressor.

One thing to do is watch that the cabinet is grounded, I used get fairly spectacular static shocks off mine at first... from the rim of the holes where the gloves are mounted.