pressure pot blaster

[mike k]

I am looking for advice from those who use pressure pots.

I have just bought a cheap sealey pressure pot blaster

http://sealey.co.uk/PLPageBuilder.a...rogroup=1346&analysiscode=&requiredresults=16

when removing the threaded cap there was a lot of swarf and light machine oil so no doubt the whole pot is the same. What would be the best way to clean out the pot. Is it just a case of disassemble, spray some cleaner followed by a pressure wash and blow dry. Obviously I don't want to contaminate my media or have any surface rust forming inside the pot.

what did you guys do?

Your experience is much appreciated

mike

 

[brightspark]

hi there just a few things . just wipe the threads clean. tip it upside down and wipe round the pot with a rag from the filler neck then a quick blow out with an airline . and if it allready hasnt got one buy a tungsten carbide blast nozzle and cut the existing one off the end and fit the new one then operate from the air supply shut off tap as here . dont wurry about a bit of rust .the inside will sweat whatever u do

 

[mike k]

Thanks brightspark, I plan on fitting a tungsten carbide tip - seen these on ebay

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=321324126598

with only having a 3hp comp with 9.5CFM free air delivery at 60psi the ceramic tips are really no good as it over works the motor as they wear so quickly so hoping the 2.5mm tip should solve that problem. I should have stated that I plan on plumbing the pressure pot - to reduce work load on comp compared to the siphon system - into my blast cabinet where I blast mostly cast ally parts so hence me wanting to reduce contamination as I will be reusing the media. I was planning on running a foot pedal as the dead man handle isn't really practical - never mind uncomfortable - for use in the cabinet. I seen a pinch valve on amazon but was wondering if they really are that practical or will they wear out fast as it seems that the diaphragm will be worked hard

http://www.amazon.co.uk/AIR-PRO-PINCH-Polypropylene-Sleeve-Valves/dp/B00AFT8EV8/ref=sr_1_3?s=diy&ie=UTF8&qid=1392392467&sr=1-3&keywords=pinch valve#productDetails

Here's a good video

http://m.youtube.com/results?q=pressure pot 102&sm=

mike

 

[rtbcomp]

If you want to control the air to the pot use a washing machine valve.

If want to control the media blast, don't bother, in a cabinet you're not going to lose the media. Just point the nozzle into the bottom of the cabinet.

 

[RonMig]

I have just bought a cheap sealey pressure pot blaster
http://sealey.co.uk/PLPageBuilder.a...rogroup=1346&analysiscode=&requiredresults=16

Just curious - when you say cheap, did you buy the one in the link you attached for £252, or this one I just found on th e bay which looks identical but costs only £89?
http://www.ebay.co.uk/itm/Sandblast...Air_Tools_and_Compressors&hash=item3a7cc95bce

or is the £89 one in some way inferior? I ask mainly as I'm also in the market for a cheap blast pot... and to me, £89 seems about right but £252 is way over the top...

thanks!

 

[rtbcomp]

I bought the EBay 20 gallon version for about £80 a few years ago.

Machine Mart sell the same thing too

 

[brightspark]

even if u use a foot switch or the inlet ball valve u will still have to pressurise the pot and wait for it to de pressurise before it stops its not like a suction gun that just stops and starts instantly

 

[rtbcomp]

True, but sometimes switching the pot off & on can restart the flow if it stops, especially with very fine media.

It's also useful to be able to hold the nozzle whilst starting and stopping the pot.

 

[brightspark]

all i do is sit the pot on a step up .the blast hose is just pushed through the arm holes at the front of cabinet and i just use rubber gloves the arm holes dont need sealing as the woodchipper can exhaust more than the blast pot can supply in air creating a vaccum of air inside the input ball valve and the media regulator underneath can easily be operated as there both within hand reach as well as holding the blast hose

 

[mike k]

If you want to control the air to the pot use a washing machine valve.

If want to control the media blast, don't bother, in a cabinet you're not going to lose the media. Just point the nozzle into the bottom of the cabinet.

Air to pot is no problem, just thought a foot pedal would makes things much easier and more efficient but the pinch valves aren't cheap and I can see them wearing fast as it has quite a job too do. Did think about just using a air tap valve but they seem to wear vast too . basically I'm trying to do things to make the blasting process as simple and uncumbersome as possible.

Just curious - when you say cheap, did you buy the one in the link you attached for £252, or this one I just found on th e bay which looks identical but costs only £89?
http://www.ebay.co.uk/itm/Sandblast...Air_Tools_and_Compressors&hash=item3a7cc95bce

or is the £89 one in some way inferior? I ask mainly as I'm also in the market for a cheap blast pot... and to me, £89 seems about right but £252 is way over the top...

thanks!

No I didn't pay that, they were on promotion plus I get extra discount on top. Basically the guy I buy my car parts from gives me trade prices so I try and put as much business his way as sometimes I don't buy much from him, swings and roundabouts. Also if there is any problems which there often can be with cheap stuff there is no problem and no return postage too pay. The sealey model has better fittings than the ebay/machinemart model but not much in it as they come out of the same factory in China. For example I bought a sealey moisture trap and they where from a bad batch and 3 times I had to exchange, if I had to pay return postage I would have lost out never mind the hassle involved and I would rather give Terry the commission than putmoney in machinemarts/harbour freights pockets.

even if u use a foot switch or the inlet ball valve u will still have to pressurise the pot and wait for it to de pressurise before it stops its not like a suction gun that just stops and starts instantly

Didn't know that, thanks.

I still think the foot pedal would be best for me, any input on wear rates and best place to buy from?

 

[brightspark]

Air to pot is no problem, just thought a foot pedal would makes things much easier and more efficient but the pinch valves aren't cheap and I can see them wearing fast as it has quite a job too do. Did think about just using a air tap valve but they seem to wear vast too . basically I'm trying to do things to make the blasting process as simple and uncumbersome as possible.



No I didn't pay that, they were on promotion plus I get extra discount on top. Basically the guy I buy my car parts from gives me trade prices so I try and put as much business his way as sometimes I don't buy much from him, swings and roundabouts. Also if there is any problems which there often can be with cheap stuff there is no problem and no return postage too pay. The sealey model has better fittings than the ebay/machinemart model but not much in it as they come out of the same factory in China. For example I bought a sealey moisture trap and they where from a bad batch and 3 times I had to exchange, if I had to pay return postage I would have lost out never mind the hassle involved and I would rather give Terry the commission than putmoney in machinemarts/harbour freights pockets.

Didn't know that, thanks.

I still think the foot pedal would be best for me, any input on wear rates and best place to buy from?

a foot pedal wouldnt wear out as it only passes air its the blast jet on the end that wears out .your best changing it to a 3mm tungsten jet available from ace engineering . just cut your existing end off and fit the new jet on using a jubily clip as in the picture i posted

 

[mike k]

I know the foot pedal won't wear out, but the pinch valve which opens and closes allowing the media through like in this video "pressure pot 102" that I linked in a previous post

http://m.youtube.com/results?q=pressure pot 102&sm=1

here is the pinch valve


http://www.amazon.co.uk/AIR-PRO-PINCH-Polypropylene-Sleeve-Valves/dp/B00AFT8EV8/ref=sr_1_3?s=diy&ie=UTF8&qid=1392392467&sr=1-3&keywords=pinch valve#productDetails

I fully intend on fitting a 2.5mm tungsten jet and fit as per your picture as that looks like the best solution but would like a simple way to switch the media flow on and off without using parts that will wear out fast.

unless I'm missing something obvious, nothing unusual for me, but looks like the media travels through the valve and the only thing that stops it is a rubber diaphragm so I'm wondering how quick they wear out?

 

[brightspark]

I know the foot pedal won't wear out, but the pinch valve which opens and closes allowing the media through like in this video "pressure pot 102" that I linked in a previous post

http://m.youtube.com/results?q=pressure pot 102&sm=1

here is the pinch valve


http://www.amazon.co.uk/AIR-PRO-PINCH-Polypropylene-Sleeve-Valves/dp/B00AFT8EV8/ref=sr_1_3?s=diy&ie=UTF8&qid=1392392467&sr=1-3&keywords=pinch valve#productDetails

I fully intend on fitting a 2.5mm tungsten jet and fit as per your picture as that looks like the best solution but would like a simple way to switch the media flow on and off without using parts that will wear out fast.

unless I'm missing something obvious, nothing unusual for me, but looks like the media travels through the valve and the only thing that stops it is a rubber diaphragm so I'm wondering how quick they wear out?

just had a look at the vid the diaphragm is sited close to the mixing tee piece so the media wont have picked up a lot of velocity till it travels along the blast pipe so should last a good while . and presumably u can replace the choke sleeves reasonably cheap

 

[mylesdw]

Those seem good videos, I may try the standpipe idea since my blaster often stops flowing the medium.

I'm puzzled by the air operated pinch valve, the video mentions that it needs a pressure differential of 3 to 4 times that of the pot. So blasting as 100psi would need 300-400 psi for the valve to work, or did I misunderstand something?

 

[brightspark]

Those seem good videos, I may try the standpipe idea since my blaster often stops flowing the medium.

the main reason the flow is hit and miss is that they use ball valves to meter the media. there not the best of idea but are cheap and cheerfull. i make my own . they regulate accurately from 1.5mm grit down to fine sand no problem and dont block up

 

[mylesdw]

Gosh that looks neat, maybe a little lathe project there! What is it made of?

Would a simple gate valve do the same job?

 

[rtbcomp]

Another reason for poor media flow is if the grit is very fine or damp it sticks in the pot. A column of grit is expelled, leaving a hollow "pipe" surrounded by grit.

If you close the bypass valve and air still flows, then this is what has happened. De-pressurising the pot will cause the media to collapse into the centre and you can start blasting again.

 

[brightspark]

Gosh that looks neat, maybe a little lathe project there! What is it made of?

Would a simple gate valve do the same job?

just made of mild steel , a gate valves no diffrent to a ball valve as the media is just piled on top of the gate.any iregularity in grit size soon blocks them up .the outlet on the ones i use are slightly raised the media falls down out of pot and spreads over the regulating plate and slightly fills the chamber so theres no direct pressure and weight of media on the regulating outlet .any of the larger particles that normaly stop the flow just fall to one side and dont cause blockages they only need taking apart and clean out once in a blue moon

 

[rtbcomp]

There are some commercial metering valves based on a gate valve, they have a silicone rubber liner which eliminates the step and prevents the grit from building up.

 

[brightspark]

There are some commercial metering valves based on a gate valve, they have a silicone rubber liner which eliminates the step and prevents the grit from building up.

i have one here . there only fitted on large blasting pots as u cant regulate them acurately enough on small pots they have a 20mm bore un choked and run up to over 300cfm setups