Used my blast cabinet for the first time last night. Worked great! Well, at least for about 10 minutes until the cheap nozzle assembly on my pressure blaster broke.



The ON/OFF switch is a 3/8" ball valve. The abrasive (coal slag) blew a hole in the side of it. I may have contributed to the problem because I was regulating the output flow with this ball valve instead of dialing down the input pressure. Instead of opening it all the way I had it about 2/3 open which may have exposed the softer brass sidewall. What material is the valve of a typical ball valve made of? Would it last longer than the brass if I opened it all the way? Still, I can't believe it didn't last longer. It's probably for the best. I had to quit when the valve broke and it was already midnight. I might have been up all night if it hadn't broke.

 

I've been really looking at the article to start working on my cabinet soon. Not wanting to sidetrack you post but what air compressor are you using? cost?

rey

 

It wouldn't be FTE if a thread stayed on topic for more than a couple posts, now would it? I bought a Porter Cable CPLKC7080V2 (made by DeVilbiss) which is a two stage, 7 hp, 175 psi, oil lubed compressor. It originally retailed for $799 at the local Farm & Fleet but I got it on sale for $769. In addition to that, I signed up for their credit card which knocked off another 10%. I probably spent $200 on electrical and air fittings and accessories to get the compressor operational. $65 of that amount went towards a breaker for my obsolete electrical box.

I haven't added everything up but here's a rough guesstimate:

$725 - Compressor
$120 - pressure blaster
$200 - miscellaneous accessories
$200 - cabinet building supplies and abrasive

Having a blast system in my garage - priceless!

I'll have more complete cost details on my web site soon. Basically, I spent as much as I could afford on the compressor. I'm hoping it will be a while before I outgrow its capacity.

By the way, does anyone have any pressure blaster setup tips? I read on one web site that the proper air/abrasive mixture would be 100 psi while backing off the amount of abrasive unitl it isn't visible in the air stream. Didn't say if you should look as closely as possible at the stream or hold it at arm's length. I just love these accurate directions. At any rate, I had it setup at about 30-40 psi last night with the abrasive valve wide open. Maybe I had too much abrasive in the mix? It did clean well.

 

Kevin,

Glad you got your cabinet working! I really love reverse-spray painting too. Matter-of-fact, I'm going out right now to reverse-spray paint my radiator support.

I can't imagine the manufacturer would EVER want abrasive and air mix going through a ball valve at any time. Are you sure the ball valve isn't supposed to be on the air inlet side?

Ball valve components can be made from just about anything from plastic to superalloys. Generally they are brass or steel. Still, I don't know of anything hard enough to withstand a grit/air flow for the long haul. That's why you have to replace the nozzle and air jet in your blast gun periodically, even though they are ceramic and hardened steel.

I'm very curious about the location of that ball valve on your system.

 

Fat Fender

I agree with Earl. I have never seen anything on the discharge side only on the sulpply side. I was in cryogenics for a while and we used ss valves but they wont stand the grit either

 

Kevin

There ain't no way that's right.

Jet Jock

I see you're new to FTE and have a 302. Welcome. Put us down for another SB Niolon.

 

The 10 gallon type import pressure blasters mostly all use 3/8" ball valves even at the output. It is considered a throw away part.

I can usually get thru 100 lbs of Black Beauty with a brass one before it blows thru the side, maybe 200 lbs with silica sand. The Black Beauty eats out a ceramic nozzle in around 100 lbs also but Im just using the cheap 5 for $3 replacements.
Plus Im set up for 70-110 psi for most of my work.

My blaster came with 4 brass ball valves.
Air input
Pressure Pot bypass
Media feed at bottom of pot
Output

Ive seen another Chinese blaster with steel ball valves, dont know how long they last. However it doesnt have the bypass line/valve which I think is an important part of setting up an efficient use of media.

As far as the output media stream you only want enough to do the job. That will vary depending on the work piece but generally I cant even see the stream.
Ive blasted my car trailer, a few dozen wheels (solid & wires), and a fair amount of 20-30's vintage sheet metal, brackets, frames and similar. Mostly Model T and A.

I havent found steel valves at the local Home Depot, time to look around some more I guess.

Cant complain about the blaster, for $75 it even came with a gauge, pressure relief valve and water seperator.

The next step is a cabinet. The latest Auto Restorer Magazine has a rather lengthy construction article on using a 55 gal drum as well as a full pressure vacuum system. Looks well thought out and rather unique in some features.

 

[QUOTE]Originally posted by fatfenders



Jet Jock

I see you're new to FTE and have a 302. Welcome. Put us down for another SB Niolon.

Thats Thornton,Fenders!
He don't count!

 

Hey Purple you were not suppose to notice. What is this "he don't count"????

Just because I shed my conservative handle (at the urging of the wiser and more established FTE members) doesn't mean I am going to lay down and let some big block run over me

 

Well, I learned something new. Seems like there oughta be a better way to regulate the flow, but if it works, go for it.

Carl, you can get 3/8" steel valves from McMaster-Carr for about $20 each. Search for part number 4631K21. Don't know if the steel will last enough longer to make it worth the extra money.

One other thing you might try is a PVC valve. I know you probably think that's crazy, and generally plastic doesn't hold up as well as metal. In this application though, the plastic absorbs the impact energy of the grit and may actually erode more slowly than the metal. I've noticed that my plastic grit feed line isn't worn at all but all the metal fittings are slowly eroding. Just a thought - considering the valve is a throw-away part and the PVC valves are probably cheaper than the brass ones anyway.

One other thing, Carl. As a personal favor, could you use one smiley in one of your posts? It doesn't have to be the smile - it could be the cussing guy. It would make my day.

 

[QUOTE]Originally posted by Jet Jock
What is this "he don't count"????

I..I..I meant he can't count you twice....Yeah, thats what I meant.

 

"The 10 gallon type import pressure blasters mostly all use 3/8" ball valves even at the output. It is considered a throw away part."

Carl

I am curious what kind of nozzle I have now that you say that. It has lasted through probaby 1000 pounds of sand. Its a squees handle, but not a dead man switch stye. It's been a clogging piece of crap since day one, but no blow through so far. It's a Chinese blaster about twice as large and expensive as yours. Still a cheapie though. They came way down in price shortly after I bought it.

Purple

Of course it's Bill, and he was flying stealth until you blew his cover.

Earl

Carl's going to use a smiley someday. He's just waiting for FTE to introduce one that says what's on his mind. You know, something like "Shut up pocket protector boy, you're gettin on my nerves again!"

 

"Pocket-Protector Boy". I like the sound of that. Could be a superhero movie in the works ...

 

Yep, this is one of those 10 gallon type import pressure blasters. At least now I know I should open the ball valve all the way to extend the life a little. How much longer would one of those deadman valves from Eastwood last? I paid $5 at Menards last night for a replacement 3/8" ball valve. That could add up in a hurry but I'd still have to go through about 15 of them before the deadman valve would become cost effective at $70 plus shipping.

 

<b>Carl

I am curious what kind of nozzle I have now that you say that. It has lasted through probaby 1000 pounds of sand. Its a squees handle, but not a dead man switch stye. It's been a clogging piece of crap since day one, but no blow through so far. It's a Chinese blaster about twice as large and expensive as yours. Still a cheapie though. They came way down in price shortly after I bought it. </b>

Dewayne, I have one of those squeeze types also, came off a 20 gal Power Craft blaster. Clogs faster than the ball valve!

I suppose I could always use a bigger nozzle as the compressor will keep up for wheels at least. But even tho I get media at wholesale, Im still a cheap New Englander at heart.

Biggest problem Ive found is moisture. As soon as you open the bag it starts to suck it up and since I do all my blasting out behind the shop it doesnt take long for clogs to develop.
Thats one reason I want to get a cabinet built.


And whats with this smiley thingie anyway? I use them a lot when the subject requires it. Just dont believe in overkill