[Sylvester Calzone]

I just purchased a sandblaster,
just wondering what media I should start with?
anything thats better then others.

I am reading that real sandblast hoods pipe in fresh/filtered air from the compressor.
was planning on using a half mask with the two cartridges on the sides, seems that non are rated for abrasive blasting?

 

[k0jdd]

i use coal slag ... aka "the black stuff"
you can re-screen it and re use it

you need eye protection and a mask...
i use a hood when its not too hot out - the rebound stings!

i place a 20x20 blue tarp on the driveway, place the work in the center, and collect the used media that way for easier cleanup

 

[mikebramel]

coal slag/black beauty

 

[troll]

I use silica sand and/or steel filings. The use of eye protection and spec'd mask are paramount with this stuff.
Troll

 

[Sylvester Calzone]

cool! I got the black slag, and a sandblast mask.
I am going to try and stay away from any silica media.

another question, when you guys say to re screen the media, how do go about doing this?

thanks for the help guys :thumbsup:

hope it all works out. I have LOTS of blasting to do :wtf:

 

[Hydriv]

If you don't have an air compressor capable of delivering a constant 15 cubic feet of air per minute at 90 PSI on a 60 gallon tank, then your sandblasting adventures are going to take a lot of time.

When blasting anything, make sure you are at least 20 feet away from vehicles, buildings or anything else that matters. Sandblasting is a dirty, nasty, boring procedure and you need a full hood, not just a mask. The media will get into every crevice of your body and anything that is close by. You have to be careful not to overdo the blasting because you can warp sheet metal if you focus on one area too much. Once you have blasted steel clean, you need to treat it quickly or it will flash-rust in no time at all. I believe that oxalic acid is what you use but you can Google that to be sure.

 

[Sylvester Calzone]

all good on the compressor, and yes its a full headed hood.
new about the rust, but didnt know about the treatment. I thought maybe shooting primer right after would also work?

 

[Hydriv]

all good on the compressor, and yes its a full headed hood.
new about the rust, but didnt know about the treatment. I thought maybe shooting primer right after would also work?

http://www.hotrodders.com/forum/flash-r ... 00635.html

http://www.autobody101.com/forums/viewt ... 10&start=0

Since you like U-Boob vids so much, I'm tossing this in.

http://www.ehow.com/how_5703340_prevent-flash-rust.html

 

[mjodrey]

new about the rust, but didnt know about the treatment. I thought maybe shooting primer right after would also work?

The new "thing" at the body shop these days is after you sand blast to bare steel,or sand down to bare steel,shoot a coat of epoxy primer on.This does two things:
1: It protects the metal from the damp air if it is going to sit a while,and is a very good corrosion fighter.
2: Epoxy primer is a good adhesion promoter,meaning what ever you put over it has a better chance of sticking,be they body fills,primer surfacers,filler primers,or top coats.

It used to be that you were supposed to put your body fill directly over bare steel,but that has changed with the newer technologies.

Maynard :canada:

 

[Sylvester Calzone]

let me bump this up.
Hydriv I like your specifications for a sandblaster.
I am now looking for one so I can use this pressure pot conveniently at home.

I am using princess auto to find a compressor. not sure about the brand.
anyways, here is a

60 gal
Full Load Current 22A
Motor 208/230V
Max. Pressure 140PSI
Tank Capacity 60gal.
Number of Cylinders 3
Starter Required No
Air Delivery @ 100 PSI 18.5CFM
Horsepower 5HP
Current Type AC

price 1000
seems good right,
http://www.princessauto.com/pal/product ... Compressor

then a 80gal

Motor 240V
Max. Pressure 155PSI
Tank Capacity 80gal.
Pump type Cast iron
Number of Cylinders 3
Air Delivery @ 90 PSI 14CFM
Horsepower 4.7HP
price 700 on sale.
http://www.princessauto.com/pal/product ... Compressor

they have this onsale instore but, its gas. I do see advantages of this but not very practical
http://www.princessauto.com/pal/product ... Compressor

the 60 gal seems like it would be great, but the tank capacity is smaller.
they do have 100 gal and up but that is special order and mucho money.

I am just shopping right now, getting more educated for the right time as I am not in any rush.
not sure if I should buy one of these or find something more industrial?

 

[mikebramel]

2nd what Maynard said on the epoxy primer. Really the best way to go. SPI is a good brand not sure if you can get it in Canada

 

[Hydriv]

Well Grasshopper,
Just so you know, expect to pay two grand and up for a true industrial duty compressor. You don't need that quality unless you intend to open up your own sandblasting shop and run that compressor 8 hrs a day, every day.

The gas powered compressor is a two-stage unit that is capable of storing air at 175 PSI. A 2-stage sucks air into a large diameter cylinder, compresses it and then passes it to a small diameter 2nd cylinder that compresses it even further in order to get to 175 PSI.

The two electric compressors are both single stage but they use three cylinders feeding into a common line that is connected to the tank (receiver). Each cylinder comes up on the compression stroke every 120 degrees of rotation. Single stage compressors do not compress the air to a point higher than 140 PSI.

If this was just supposed to be a home shop compressor capable of running some air tools such as impact wrenches and air ratchets etc, then the $700.00 unit would be my choice. However, you want to run a pressure pot sandblaster and so you have to look at the number of CFM's as well as the pressure those CFM's are delivered at. The $1000.00 unit would be my choice for that application due to the bigger pump. It seems a bit weird that this one has the 60 gallon tank and the other one has the 80, but that wouldn't influence me because it's not about the size of the tank.... it's about the size of the pump.

Pressure pots have a ceramic nozzle on the end of the hose. Different size orifices are available. Smaller orifices use fewer CFM. All orifices increase in size as you use them. What you want to happen is for the compressor to run steady and constantly deliver 90 PSI of air to the pressure pot at whatever CFM the nozzle needs. Having the compressor start and stop, start and stop, start and stop is pointless. That just shortens the life of the starter switch.

 

[Sylvester Calzone]

CRAP
thats what I was thinking but was hoping I was wrong.
I thought the 80 would have a better pump then the 60.

the 80 is more inline in what I wanted to spend.
so when you say its pointless for the compressor to start and stop, your saying you would just keep it running while your blasting?
I am use to letting the compressor build up and shut off to cool, but these are small ones at home.

for some reason the gas one was around the 80 gallon price may have been a mistake, almost seems this one would be better for sandblasting.
still, gas? :think: maybe I can bolt it into a bed of a truck and inflate tires and sandblast mobile :lol:

 

[Hydriv]

The link for the gas unit says it's $1500.00 and it puts out 80 CFM.

For $1000.00, you are still getting 80CFM.

You should talk to one of the people in the store. Ask them to punch in that SKU and see if that compressor has ever been on sale.


A compressor is usually a once-in-a-lifetime buy if you choose wisely. Used compressors don't bring much on the open market because no one knows how many hours are on it and whether it's been looked after or not. You could go with the other one with the 80 gallon tank but the CFM is less. You are losing 4 1/2 CFM and that's a lot when you are talking about a high consumption tool such as a pressure pot. And that CFM is also being delivered at 10 PSI less than the 60 gallon unit.

What I'm saying is that a perfect balance between a compressor and a pressure pot would be that the pressure pot consumes air at the exact same rate as the compressor produces it. If you can fire media at the object to be cleaned at 90 PSI to 100 PSI on a constant basis, then that's perfect. The compressor doesn't get to fill the tank and shut down...... only to restart once again 30 seconds later when the pressure in the tank falls to the cut-in point on the switch. But since you brought that subject up, you should also ask what the Duty Cycle is for the motor on these compressors. Some compressors are sold with motors that will burn out if you run them steady. They are rated for home use only with the expectation of very intermittent use.

Maybe you'd be better off with a used industrial unit from a Pro compressor shop that takes trade-in's and refurbs them. The more you phone around and talk to the Pro's, the more you will learn about compressors. One of the very best pumps out there is made by Quincy. These have a pressure lubrication system and if the oil is low, then the pump will spin but it won't make air pressure because oil pressure is needed to let the valves work. That alerts you quickly to a low-oil problem before it gets nasty.

You will also learn about electric motors and how they come in different "frame" sizes even though the HP rating can be the same. Industrial compressors use large frame motors so that they can run non-stop and easily dissipate the heat. Let your fingers do the walking with your Yellow Page directory. Tell them what you are trying to do. They will help with advice.

 

[markgru02919]

When I worked at Electric Boat I would grab some overtime in the paint department, I ended up sandblasting every time I was there because nobody else wanted to do it. Young family had to do it as much as I hated it. My throat is drying out just thinking about it. We use to use-steel shot or powdered glass depending on what we were blasting. If you want to be a little more comfortable when sandblasting, throw the sandblast hoods out. Take a face shield, some long rags or old bed sheets if you have them. Duct tape the sheets all around the face shield and let them hang at a minimum below your waist. Knee length is better, the rags or bed sheets should be taped and sealed all around the face shield and your upper body should be completely covered with the rags / bed sheets as they hang off the face shield. Similar to a Beekeepers suit except everything is suspended off the face shield, wearing one-piece jump suits unnder the face shield with the rags will make the job a little more comfortable. Also wear a Balaclava and safety goggles under the face shield and ideally use a fresh air supply respirator.
Do not use a grinder or any rotating tools when you have the face shield and long rags / bed sheets on. Sandblasting has to be one of the worst tasks to perform. I prefer to use chemical strippers to remove paint and minimize sandblasting.

 

[gator_rider2]

http://www.tractorsupply.com/air-compre ... or-3301332

A single stage with 2 pistons 5 hp is more suited for sand blasting and painting a single stage has 2 piston same size so pump time be less if get double stage you get large piston and small for higher pressure the small piston pump at low CFM.

One above just like mind but I purchase in 2005 with 80 gallon tank on tare down large Diesel 6 cylinder mind pump up one time if start with full tank. Compressor runs a lot while sand blasting and painting but there not shortage of air or pressure.

 

[Chris Gorling]

Ok everything has been covered as far as the physical components to the system go. You can get aluminum oxide in different grades meaning size of the media. The finer the media the smaller nozzle tip you will be able to run without plugging the whole line from tank to nozzle. You will do this a few times when learning and have to take the nozzle off and clear the hose. 14 scfm should be enough, 11 would even get the job done if you get nozzled down with finer media. As stated before, once you get the system tuned the pot pressure will ride at an equilibrium with the compressor tank and the compressor will run 100% of the time till you take a break or finish. Most smaller jobs will be run to completion because you may plug the line if you stop with this type setup. It's not an industrial rig but it'll get-er done. We're talking garden tractors here, and it does me just fine for full size tractors as well.
Those Princess auto compressors are made in China, and the chinese suffer on metallurgy. The castings will be fine, but little things like reed valves will fail. Make new ones out of the real nice springy stainless scrapers they have there and put a backup shim on top where the reed extends from the clamp. That's where it bends and work hardens and gets brittle and snaps. Hopefully the pieces won't wind up on the piston. Take the head off and have a look. Locktight the reed nuts so they stay put and you won't be in that head for a while.
My first compressor was a Campbell Hausfield Cast Iron series and I changed reed valves in it lots till it ate the reed nuts and piled up. Then I tried one of those three cylinder chinese pumps on the same motor and tank and it vibrated so much I took it back. Back to the chinese duplex with the nice reed valves I made after theirs snapped and it runs nice. Pulleyed up to max RPM, with a copper coil for an aftercooler before the air out hits the desiccant dryer before winding up in the tank. Same motor chugging along for the last 20 years and it gets more use than intermittent some days. Wait till you run some orbital sanders and you'll understand what it means to have the pump running 100% of the time, throttling on your inlet valve and using just enough hand pressure to keep the rig running at optimum.
Whatever you get if you use it enough you'll learn how to use it. If you just want to go play once in a while better get the big bitch cause it'll be intermittent on-off filling up the tank while your unplugging hoses anyway.
My 2 cents
Chris

 

[Sylvester Calzone]

thanks for the responses :thumbsup:
I just became aware of oil separators, always knew that air dryers are a must but what is a oil separator for?
is it if you use one of those air fed hoods?

one I stumbled on
http://www.princessauto.com/pal/product ... -Separator

about the compressor, I told my neighbor I am looking for one to get more advice. He said his brother is trying to rid of a 220v vertical compressor that came out of a automotive shop. guess I will see what that is about first.

 

[Hydriv]

An air compressor isn't that much different from any common internal combustion engine. You have a crankshaft, pistons, rings, valves and so forth. They can be lubricated via an oil pump or they can be splash-lubed like a Kohler K. The point is this. OIL can get past the rings and into the combustion chamber which is called the compression chamber on a compressor. That oil can end up in the air receiver where it can mix with the air leaving the receiver just as moisture can. The last thing you want is to have oil sprayed onto whatever you are painting because it will ruin the finish.


Now you know.

 

[Kenc]

http://autobodystore.com/forum/showthre ... oxy-primer[/URL]

and read the pros take on rust/primer/treatment/epoxy/filler etc. Test by these guys have convinced that filler on metal is best.