Sand blasting info needed.

[Georgia Iron]

I acquired a 375 cfm ingressol and rand diesel rotary screw compressor. It cranks and runs. It is a older unit. I am looking at getting a sand blasting set up going.

I will need to.find a pot and a hood and a deadman either air or electric.

any one have suggestions on a proper setup and what is safe to use. My compressor does not have a regulator as far as I can tell so I was wondering how you step the air down to safe levels such as 20 cfm for a hood and 50 psi or what ever pressure a pot will need.

The amount of air that comes out of the compressor is a heck of a lot and I have not figured out if it is always putting out so much and how it meters the air since I don't have anything that attaches to it.

is it possible to use damp sand?
I have a ton of it that's been exposed to the weather. maybe if i dry it out somehow.

i have been looking a pirate blasting equipment and also at stuff on ebay.

I need to clean some excavator bottom ends and some of them have a fair amount of rust and scale.

 

[1693TA]

The air compressor is just the beginning. You are going to spend some money to get started; no way around it. Clean, dry air is an absolute must so filtration and drying is required. This in itself is expensive as the air directly out of a compressor will foul your media on short order if run straight. To pull fresh breathing air from that compressor requires another filter/regulator setup that monitors for carbon monoxide gas which will be present in the air compressor's discharge air stream. This is not from the engine, but rather from the heat of vaporization of the lubricating oil used in the screw portion that makes the compressed air. Don't even think about using wet media as you'll spend more time down than up cleaning fouled lines and media regulators.

You are going to need a lot of questions answered. The folks that market the "Pirate" brand of blast machines are very good and know their business. Can't speak for ebay vendors myself but I always deal with the office out of Indianapolis. IDS Blast is their name and I get quite a bit from them. Another very good vendor is www.sandblastingmachines.com https://sandblastingmachines.com/ Talk directly with "John" there as he will tell you straight without trying to upsale you on anything. He has helped me greatly when setting up my blast line.

My portable blasting equipment is "Clemco" and there is a reason for that. Costs more up front, but very high quality that will go the distance. That's not a sales pitch, it is truth.

 

[Legdoc]

I will second Clemco equipment.

 

[Welder Dave]

I helped a sandblaster once. I had to add sand to the pot everytime he stopped to reposition. You couldn't add sand when he was blasting. I had to listen for the compressor to idle down and then throw a bag or 2 of sand in the pot. A big compressor goes through a lot of sand in a hurry. I would set it up so your not using the max. output of the compressor all the time. I think compressors might have duty cycles like welders. Running at max. CFM all the time could shorten the life of the compressor.

 

[crane operator]

You may be able to screen/ dry your sand by laying it out on a tarp in a shallow layer, and let the sun do its thing. A lot of guys will recycle their sand by a tarp/plastic under whatever they are blasting.

The rotary screw compressors are 100% duty cycle. It should have it own dump valve that cycles to keep from excess pressure. You should be able to put in a inline regulator to drop pressure for your hood.

You should also look for your unemployed cousin's nephew, and pay him cash to do it. Sandblasting is a miserable job.

 

[Truck Shop]

Sand blasting can be expensive {in some cases}. My dad built a 25' building on skids to make
sand blasted wood signs. Keeping the moisture out was the biggest issue along with filtering
the sand which stayed contained inside the building. At the time we had the biggest Imglo
I think that's right for a compressor with a huge for the time water separator made just for
this type of work. The biggest sign we did was 20' x 7' x 8" thick solid Redwood glued and tie
bolted. It was for a major water bed company {remember those}. this was in 1978 and the
price to make/build this sign was stupid expensive. And after water beds became passe I
imagine it got cut up/scrapped and or a huge head board made out of it. It was on the cover
of a national sign industry magazine called Signs of the Times.--Trivia on sand blasting.
*
I was the one who blasted it.

 

[1693TA]

One needs about 100cfm at 100-125psi to be productive. This will wear a guy out standing still holding a blast hose, (which is heavy) aimed at an object to strip or remove a coating from. Rule of thumb is you need a blast hose three to four times the diameter of your nozzle, or larger. I use a 1.250" diameter hose and it works very well with a 3/8" blast nozzle. Excellent in fact. There are straight, single and double venturi nozzles available along with different construction composition. There are also pressure hold, and pressure release systems. Lot's to learn for the beginner.

Screw, vane, and/or piston compressors that are continuous duty use an unloader system which doesn't dump any air but rather opens valve that disallow further compression of air. This is how the engine can keep running but not build further pressure. My IR rotary screw unit is 850cfm and will run 125psi constant with the draw I put on it with all my cabinets running together. My largest cabinet uses about 100cfm and the smaller tumble blasters use about 20cfm each. Regardless, I never hear the 6V-71 Detroit come up to high idle as I just don't pull enough air it needs to speed up so runs at low idle. Now if I crack the 3" discharge ball valve fully open, the throttle comes right up and a tornado is produced for about 300' from the air blast. The air is louder than the engine too. This compressor is portable but on four wheels so really not easy to move.

For portable or remote work I use my old Worthington rotary vane air compressor. It is 250cfm and works well. There are threads on here about this compressor if you search. I've done a lot of work with this compressor over the years.

Ingersoll-Rand:



Worthington:

 

[Old Growth]

I just picked up a trailer mounted Ingersoll Rand 100. p-100b-w-w. Its 100CFM and 100PSI.

I have a smaller blasting pot. I also just picked up 120 gallon tank. I would like to be able to blast automotive things like frames and random equipment like trailers etc. I don't plan to blast whole machines like dozers and hoes tho.

I have no clue what I'm doing so I will be following along closely.

 

[Legdoc]

I just picked up a trailer mounted Ingersoll Rand 100. p-100b-w-w. Its 100CFM and 100PSI.

I have a smaller blasting pot. I also just picked up 120 gallon tank. I would like to be able to blast automotive things like frames and random equipment like trailers etc. I don't plan to blast whole machines like dozers and hoes tho.

I have no clue what I'm doing so I will be following along closely.

I have done quite a bit of blasting with a 185 CFM compressor and painting. I can not over emphasize safety for the operator and anyone in close proximity. One must be concerned about blast dust, possible lead exposure from old paint, carbon monoxide exposure, usual dangers of dealing with compressed air... I would go to YouTube and watch the circus with people with no idea of what to do and others who do. There is really nothing overly complicated about it. I find it very satisfying to blast the substrate white and follow with high performance coatings. You might consider starting a new thread on the subject. Clemco and Schmidt Manufacturing might have safety and blasting process videos.

 

[1693TA]

I just picked up a trailer mounted Ingersoll Rand 100. p-100b-w-w. Its 100CFM and 100PSI.

I have a smaller blasting pot. I also just picked up 120 gallon tank. I would like to be able to blast automotive things like frames and random equipment like trailers etc. I don't plan to blast whole machines like dozers and hoes tho.

I have no clue what I'm doing so I will be following along closely.

A 100 pound pressure pot will carry you far once set up correctly. I have one of these from Brut and they work well for the beginner:

Pressure Fed Abrasive Sand Blaster 150H – brutmanufacturing

brutmfg.com

However be prepared to spend just as much for a breather filter setup to ensure your own safety. I have one of these of preference of two:

NV3-705-50PCCD

RESPIRATOR PACKAGE, RPB® NOVA 3®, W/ C40 CLIMATE CONTROL DEVICE, INCLUDES MEDIUM SIDE PADS, (NIOSH APPROVAL NO. TC-19C-456 TYPE CE), RPB® RADEX AIRLINE FILTER™ 50' BREATHING AIR SUPPLY HOSE, 3/8"

idsblast.com

My older setup uses a "Wilson", (now part of "Survive Air") portable air compressor unit for supplied air to the hood with a "Bullard" blast hood/helmet, but the Nova 3 uses the portable compressor and I have a "Marco" CO detector inline also. The CO detector is the next thing to be upgraded as there are much smaller available now that mount inside the blasting helmet. I have one of these to demo sometime but have not yet.

A respectable flow rate is about 5-8 pounds per minute of blast media at 100psi through a 3/8" blast nozzle. A 5/16" nozzle is a lot nicer to handle however for blasting intricate surfaces. Smaller yet for more detail work along with media selection. You mention frames and the smaller nozzle would be the cat's meow for you in this application. 1/2" blast hose is much easier and nimble to work with than 3/4" or larger and if you are all twisted and contorted to get into position, the smaller hose is an asset.

My opinion but the valve setup shown on that Brut blaster is not the best to use. It will shut the abrasive flow off but is very short lived in practicality. I retrofitted mine with a pneumatic "Pinch Valve" which pinches the blast hose near the blast pot and this is controlled via pneumatic toggle switch at the blast nozzle holder. Works slick.

Now for my one sided input on discharge air from the compressor. You really need to cool this air before it reaches the blast pot. This is done with an intercooler much the same as a heavy truck or piece of equipment uses but it needs sized correctly. Truck intercooler cores will not flow enough air through them as the tubes are not large enough internally. These get expensive but they are simply a hose from the compressor discharge to the cooler, and from the cooler to the blast pot. Usually they will have either a pneumatic or electric motor driving a fan blade to force ambient air over the tubes through the core. These work well and most use a drain and you'll be surprised how much water is captured or drained off as you blast. Many larger compressors will have this intercooler built in, but most smaller ones do not. There are other ways to cool the discharge air also if you have a garden hose and tank a core will fit readily available. I made my first cooler from an RV water holding tank and 1.5"" pipe, fittings, and a ball valve. It works slick but has been improved upon. Learn as you go type thing.....

Now that you're bored as a guy totalizing and pouring over spreadsheets 20 minutes past quitting time on a Friday evening the boss mandated done before your leaving for the long weekend 10 minutes before departing for his meeting at the yacht club, hope you have something to think about.

All kinds of opinions out there on what to do, what not to do, so on and so forth. Best talk to one of the places mentioned in an earlier post, (or the like). I have found both very honest and caring you get what you need.

 

[Georgia Iron]

I have had my eye out for a used pot at a fair price but once you actually start looking it seems none are to be found. I bet the scrap yards have gotten more than there fair share. I was considering attempting to make one out of a used propane tank but have not come up with an easy way to seal it.

 

[reganj]

It has been mentioned several times but Respiratory Protection is one of the highest priorities you should be concerned with. Once that crap gets into your lungs, do not think you breathe it back out.