[vich57]

After reading reviews for the Skat Blast S-35-M Medium Trigger-Operated Power Gun, it looks like a number of people had problems with cheap blast guns supplied with their cabinets, and this gun really helped.
It's $99 + $12 shipping, everywhere I looked.
That's about what I paid for my blast cabinet, but I'm thinking I have to at least try this gun out to see if it fixes my issues.

Skat Blast S-35-M Medium Trigger-Operated Power Gun for Skat Blast Sandblasting Cabinets, Made in USA - Amazon.com

Skat Blast S-35-M Medium Trigger-Operated Power Gun for Skat Blast Sandblasting Cabinets, Made in USA - Amazon.com

www.amazon.com

 

[BO185]

After reading reviews for the Skat Blast S-35-M Medium Trigger-Operated Power Gun, it looks like a number of people had problems with cheap blast guns supplied with their cabinets, and this gun really helped.
It's $99 + $12 shipping, everywhere I looked.
That's about what I paid for my blast cabinet, but I'm thinking I have to at least try this gun out to see if it fixes my issues.
View attachment 423956

Skat Blast S-35-M Medium Trigger-Operated Power Gun for Skat Blast Sandblasting Cabinets, Made in USA - Amazon.com

Skat Blast S-35-M Medium Trigger-Operated Power Gun for Skat Blast Sandblasting Cabinets, Made in USA - Amazon.com

www.amazon.com

The carbide nozzle skat gun will flow way more air internally to nozzle and you will never wear it out. BUT you will never beable to use it unless you have enough compressor. I mentioned compressor sizes in one of my posts

 

[vich57]

BUT you will never be able to use it unless you have enough compressor. I mentioned compressor sizes in one of my posts

The compressor size won't matter until the pressure drops enough for the compressor to kick in.
I'm having issues at 100 PSI with two tanks tee'd together for the air supply.
I would buy a 15cfm compressor if I thought that would make a difference.
I don't plan to paint or continuously drive an air sander.

Either the cheap gun is my issue, or I need to switch to a pressure pot for the media.
Smaller size media may help as well, but I don't want to use anything that would damage aluminum castings or make me at risk for silicosis.

 

[Shadetree55]

The compressor size won't matter until the pressure drops enough for the compressor to kick in.
I'm having issues at 100 PSI with two tanks tee'd together for the air supply.
I would buy a 15cfm compressor if I thought that would make a difference.
I don't plan to paint or continuously drive an air sander.

Either the cheap gun is my issue, or I need to switch to a pressure pot for the media.
Smaller size media may help as well, but I don't want to use anything that would damage aluminum castings or make me at risk for silicosis.

2 tanks tied together makes no difference. Actually can make it worse. The compressor is doing more work "longer" just to keep 2 tanks full. You can get a 10 gallon pot on amazon for not much more than that nozzle

 

[BO185]

The compressor size won't matter until the pressure drops enough for the compressor to kick in.
I'm having issues at 100 PSI with two tanks tee'd together for the air supply.

Which at 15cfm which is what that nozzle flows at 90psi will be... easy calculable using the formula t = V (p1 – p2) / C pa Given 2 80 gallon tanks, 150 start 90 kick on, you get maybe 6 min of blasting before compressor runs constantly. At 15 cfm. even with two tank you issue is lack of CFM. If you had 5 tanks it will only give you a set amount of time in CFM the nozzle needs then its limited by what CFM compressor is. If compressor is larger then you need it will run and kick off. So 15 cfm nozzle and a 25-30 cfm compressor it will cycle on and off refilling the tanks. And not duty cycling out compressor. ( this means it gets hot and blows up at some point)

I would buy a 15cfm compressor if I thought that would make a difference.
I don't plan to paint or continuously drive an air sander.

So you tanks last maybe 5 min and the rest the compressor is running constantly. You'll want an air drier or you will get water make sure to only blast for 30min and let compressor cool an hour or you will blow up a piston unit getting it to hot.

Either the cheap gun is my issue, or I need to switch to a pressure pot for the media.
Smaller size media may help as well, but I don't want to use anything that would damage aluminum castings or make me at risk for silicosis.

The above I know all to well about as I have tried it. I own a media blasting business and have tried every setup the above included. Will it work yes but it will be no fun. But will take longer and put a hurting on a compressor for it running all the time. Tanks just buy blast time which is a few mins then it will run on the compressor. You want the largest compressor you can afforded. Ideally two stage is has more CFM delivery.

Even a pressure pot will have same issues. Again from my other post the nozzle set delivered CFM. You plan around it.

For AL you want you want a fine medial like, fine coal slag or crushed glass. #40/80 Mesh you could get by with #30/60 Mesh (this is larger).

 

[vich57]

Plumbing the two tanks together did help somewhat, but not enough.
Instead of one 1/4" I.D. fitting connected to the compressor, I now have two in parallel, one for each tank. That's got to help flow, at least through the tee fitting.
Still, the blast gun itself has a 1/4" fitting on each end of the hose. But that's the same as most blast cabinets, and some of them work fine.

The few minutes of time I get before the pressure drops doesn't provide for effective blasting.
A large enough compressor will only help for continuous use, where the pressure drop would otherwise cause the blast gun to be ineffective.
I have that issue now -- even with full pressure and the compressor not needing to run.
If I had effective use of the blast gun when the pressure was up, and if pressure drops caused me to have to wait to continue blasting, then I'd buy a larger compressor.

From How To Size An Air Receiver Tank | Sizing Formula & More
t = V (p1 – p2) / C pa
where
V = volume of the receiver tank (cu ft)
t = time for the receiver to go from upper to lower pressure limits (min)
C = free air needed (SCFM)
pa= atmosphere pressure (14.7 PSIA*)
p1 = maximum tank pressure (PSIA)
p2 = minimum tank pressure (PSIA)
*PSIA = Pounds Per Square Inch Absolute; pressure relative to a vacuum.

V = ~4 cu ft (30 gallon tanks)
p1 = 110 psi (+14.5)
p2 = 80 psi? (+14.5)
C = 10 cfm (blast gun spec)
pa = 14.5 psi (we're ~380 ft above sea level)
This makes t = 0.827+ minutes, which seems a bit low.
And the pressure drop is a lot slower than the formula predicts.
If I could get close to 1 minute of good, effective blasting time, then I would upgrade the compressor to make it happy.

 

[vich57]

Choices:
1) smaller media size ($22 + clean out the sump)
2) better blast gun ($111, possibly returnable)
3) pressure pot for media (I haven't figured out what I need for this option)
4) bigger compressor ($1000 to $1800)

 

[BO185]

Plumbing the two tanks together did help somewhat, but not enough.
Instead of one 1/4" I.D. fitting connected to the compressor, I now have two in parallel, one for each tank. That's got to help flow, at least through the tee fitting.
Still, the blast gun itself has a 1/4" fitting on each end of the hose. But that's the same as most blast cabinets, and some of them work fine.

The few minutes of time I get before the pressure drops doesn't provide for effective blasting.
A large enough compressor will only help for continuous use, where the pressure drop would otherwise cause the blast gun to be ineffective.
I have that issue now -- even with full pressure and the compressor not needing to run.
If I had effective use of the blast gun when the pressure was up, and if pressure drops caused me to have to wait to continue blasting, then I'd buy a larger compressor.

From How To Size An Air Receiver Tank | Sizing Formula & More
t = V (p1 – p2) / C pa
where
V = volume of the receiver tank (cu ft)
t = time for the receiver to go from upper to lower pressure limits (min)
C = free air needed (SCFM)
pa= atmosphere pressure (14.7 PSIA*)
p1 = maximum tank pressure (PSIA)
p2 = minimum tank pressure (PSIA)
*PSIA = Pounds Per Square Inch Absolute; pressure relative to a vacuum.

V = ~4 cu ft (30 gallon tanks)
p1 = 110 psi (+14.5)
p2 = 80 psi? (+14.5)
C = 10 cfm (blast gun spec)
pa = 14.5 psi (we're ~380 ft above sea level)
This makes t = 0.827+ minutes, which seems a bit low.
And the pressure drop is a lot slower than the formula predicts.
If I could get close to 1 minute of good, effective blasting time, then I would upgrade the compressor to make it happy.

You numbers are off. And easily figureable. The .27 nozzle you posted will deliver 20+ cfm in a suction cabinet. If you have 3/8 hose and 1/4” fittings so your getting abot 15ish cfm to the nozzle that is then pushing more air out which drops pressure you may try upping psi to higher due to loss from nozzle. That is why it sucks when blasting even off the tanks alone upping pressure may help. Usually with everything setup correctly you want 80-90psi max in line to gun but if nozzle is to big you’ll loose pressure. And running smaller nozzle will help too but won’t cut as quickly area wise only.


Also it’s not going to blast really quickly anyway as it’s just not moving enough media. So I think you expectations of quickly doing part maybe your issue to being with., its not fast at all.

Example of my suction blasting setup: with a skat M-35-L the larger flow nozzle unit. I have 40cfm compressor routed via 3/4” line to a regulator to 80psi with 3/8” whip hose and fittings to gun. It takes me about 45min to blast SBC valve covers clean. On the original as delivered from HF with 15cfm compressor it would take well over an 1hr to do same part.

Yes a pressure blaster would be quicker. If I use my 5/16 nozzle 600lb pressure pot with a 500cfm screw compressor it takes 3-4 min if that.
Suction blasting is slower and doesn’t cut as quickl.

 

[55 Tony]

So you tanks last maybe 5 min and the rest the compressor is running constantly. You'll want an air drier or you will get water make sure to only blast for 30min and let compressor cool an hour or you will blow up a piston unit getting it to hot.

Exactly. It will work for a couple of minutes at a time. I think that is what he is saying. Sure it won't be fun but it will work in spurts which may be OK for the small amount he needs to do. The problem he is having has nothing to do with the CFM of the compressor.

 

[BO185]

Exactly. It will work for a couple of minutes at a time.



I think that is what he is saying. Sure it won't be fun but it will work in spurts which may be OK for the small amount he needs to do. The problem he is having has nothing to do with the CFM of the compressor.

The Compressor issue is you want more capacity then what system Will deliver meaning 15 cfm and 15 cfm nozzle the compressor is running 100% of time, and puts a hurting on it over time. Unless you have a screw compressor with 100% DC, you will Kill a recip compressor over time. How long well hard to say. If its runing alot then it will fail. Heat and duty cycle. Not just that the noise most are quite.
I think issues here are more expectation related.

 

[acardon]

The compressor size won't matter until the pressure drops enough for the compressor to kick in.
I'm having issues at 100 PSI with two tanks tee'd together for the air supply.
I don't plan to paint or continuously drive an air sander.

Either the cheap gun is my issue, or I need to switch to a pressure pot for the media.
Smaller size media may help as well, but I don't want to use anything that would damage aluminum castings or make me at risk for silicosis.

I believe you'll need a pressure pot for the walnut shells. I don't think a $100. gun will help. 20 lb. Pressurized Abrasive Blaster And they have a 15% off coupon.
I think you will be surprised what glass beads will make aluminum look like without damage and doesn't cause silicosis.

 

[vich57]

20 lb. Pressurized Abrasive Blaster

This could be something to try. $89 and it's available 10 miles away.
Coupon is good until Monday...

 

[acardon]

This could be something to try. $89 and it's available 10 miles away.
Coupon is good until Monday...

Suggestion: Locate it where you can get to the flow control valve while blasting. I have the larger pot and put a lever and link to the valve so I didn't have to stand on my head to adjust it.

 

[Alloy]

vich57,

Where in Washington state are you?

I have one of the larger harbor freight pressure blasters you could try out if you are close enough to the Longview area.

 

[55 Tony]

Suggestion: Locate it where you can get to the flow control valve while blasting. I have the larger pot and put a lever and link to the valve so I didn't have to stand on my head to adjust it.

That sounds like a great idea. I hardly used mine but I recall that valve was a pita to adjust. Do you have a picture?
IIRC, moving that valve back and forth would help a lot when the media would stop flowing.
Also when I stopped for 5-10 seconds the media would keep going and fill up the hose. Then it may or may not clear out when blasting again. It's probably been 5 years since I used it, for little stuff I use the handheld one. That works pretty well.

 

[vich57]

They were out of the smaller one in Bellevue, and I didn't want to drive around, so I just got the larger size ($136 after the coupon).
I'll figure out how to hook it up next week.
110 lb. Pressurized Abrasive Blaster (harborfreight.com)

 

[vich57]

Suggestion: Locate it where you can get to the flow control valve while blasting. I have the larger pot and put a lever and link to the valve so I didn't have to stand on my head to adjust it.

Yes, I'll probably build a shelf and tie it to the wall to make it accessible while blasting.

 

[acardon]

That sounds like a great idea. I hardly used mine but I recall that valve was a pita to adjust. Do you have a picture?
IIRC, moving that valve back and forth would help a lot when the media would stop flowing.
Also when I stopped for 5-10 seconds the media would keep going and fill up the hose. Then it may or may not clear out when blasting again. It's probably been 5 years since I used it, for little stuff I use the handheld one. That works pretty well.

That's why I made it easier to get to. The hose would fill up when I stopped blasting. I shut it off before I stop the gun. Kinda crude but works.