Sand blasting pressure pot

[Squidge]

Does anyone have any experience of running a 40 litre sand blasting pressure pot?

I’m wondering if my 200 litre Hyundai compressor would be suitable for one
It goes up to 10bar and can displace 400 litres of air a minute.

It’s more than cable to supply my blasting cabinet.


From what the seller has told me it needs a minimum of 50 psi in the pot at all times

I need to use it to sand blast a Land Rover chassis and bulkhead.

Thanks in advance,

 

[Squidge]

The motor on the compressor is 3hp

 

[Erie Fred]

Consult the chart, it will answer all your questions:

sandblast nozzle chart at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

 

[JOEPRO]

I'd say your 200L compressor will run it but you'll have to stop every few mins and let it fully charge up etc.

And be sure to use water trap(s). One normally comes on the Blast pots too.

Ideally a tandem compressor would be used with these blast pots.

Certainly anything smaller than a 200L compressor will struggle big time IMO. Others on here argue that small is the new large on compressor sizing but I am yet to be convinced in that regard!

 

[Neilj]

As @JOEPRO says your compressor will probably run the blast pot if it's got a 2.5-3.0 mm nozzle on it, but it will be stop / start as the compressor won't keep up with the air usage. You also need to think about duty cycle on the compressor, it won't be happy running full time.

 

[henry Kadzielski]

My two cents worth. In short 'NO' it won't be big enough. The 10 bar is a good pressure for a pressure blast pot, providing the pot is rated for that pressure. In 'bananna terms' every 1psi above 100psi gives you 1.5% increase in blasting performance, with the converse is also true. Now depending on the blast media and or the material to be blasted, you may not want to run at 100psi. The 100psi is for blast media like garnet or steel shot. Secondly and just as important is the nozzle size. General rule of thumb, for every size increase the air consumption doubles. Now also to consider is the blast hose. If the blast hose from the pressure pot is 'big' you cannot use a small nozzle as the air speed down the blast hose will be too low to keep the grit in suspension. This results in the uneven grit flow and the hose that seems to be convulsing. There are charts for blast hose to nozzle ratios and then also air flow requirements. I personally expect that you will need two compressors running into one line feeding the blast pot to do any good. There is no substitute for horse power 'air flow' when blasting. Yes you can do it with a small system but it takes a VERY LONG time. As @Neilj has stated duty cycle (appart from the water issues) is you next problem. Reciprocating compressors don't like to run continuously, they need rest to cool. So there you have it, hope that helps

 

[brightspark]

its preferable to run the pressure at 90psi constant .if it drops in pressure you end up using more abbrasive than air and less cutting power

 

[henry Kadzielski]

its preferable to run the pressure at 90psi constant .if it drops in pressure you end up using more abbrasive than air and less cutting power

When I am blasting I use 100psi as a minimum. My diesel compressor runs at about 8bar min and my rotary screw compressor starts back up at 7bar and cuts out at 8bar. I have very much noticed the difference in blasting speed with lower pressure. From my normal diesel system at 8 bar up to 10 bar there is a significant speed increase and every customer want's their job done faster. I have a professional set up (three in fact) and I can't go as fast as I would like, because I am limited by horse power, there is never enough. The more you have the more you want, well that is just me.
For those that don't know the lower the air pressure the lower the kinetic energy in the grit, thus the lower the impact force of the grit on the work piece which results in slower cleaning of the work piece. The only up side of this is the slower destruction of the grit (if you intend to reuse it) that's it. When I blast boats, boats are contaminated with salt, so reusing grit is a no no. So I like to get to get the max out of my grit

 

[optima21]

I have a 3hp compressor with my pressure pot, and that will run at 50 psi all day, it may take a bit longer that trying to run at 90psi, but the compressor was unable to keep up with the demand at 90psi so the pressure would rise and fall if you took a break to allow the compressor to catch up. on mt benchtop blasting cabinet, for blasting delicate items, I'll use air pressure down to 25psi.

 

[brightspark]

if the pressure rises and falls it alters the ratio of the media .if it drops you end up using more media with less cutting power . run at the constant higher pressure it will have a good cutting efficiency and use less abrasive and get the job done faster

 

[optima21]

no I think I'll stick to my way of working, its works better for the equipment I have

 

[henry Kadzielski]

no I think I'll stick to my way of working, its works better for the equipment I have

I completely understand, it is the material / process that you are doing. Horses for courses. I mainly blast steel so I need to get the crap off as best and as fast as possible

 

[fizzy]

I have blasted a 110 chassis with my Clarke 3hp 14cfm compressor. You have to use a small nozzle and it takes a while but perfectly possible. Lovely finish and back to bare metal.

 

[Dcal]

The blasting in the post below was done with a 3hp compressor and a pressure pot.
I used a 3mm nossle.
Took a while for even the small bit I did, but as @fizzy said, if you take your time it is doable.

Where a small nossle does really come into its own is if you don't want to distort light, flat panels.
Use a 6mm and you will trash a roof or bonnet.
Sometimes slow is the only option.

25 year old Alfa 75 back from the brink (hopefully)

I use Dinitrol rc900 on bare steel for the same reason....basically as a rust converter and primer...then epoxy over the top. So far I've had good results.

www.mig-welding.co.uk