New Compressor and sandblasting advice

[fizzy]

I say new compressor but I have had it a while now - never used it in anger.
A nice big Clarke 30cfm 7.5hp 3 phase.
I need to get a regulator and water trap for it. Do I go for 1/2" or 3/4"? I don't want to restrict airflow. Any suggestions?

I also have one of those 10/20 gallon pressure pots. Any suggestions for improving it? @brightspark might give me some tips here.
Almost ready to sandblast and paint my trailer - got to do it before winter sets in. Will be blasting outside - assuming we get some dry weather that is

 

[fizzy]

Oh and I need some hose
Is this suitable - seems rather cheap!

US PRO HEAVY DUTY Air Line Hose Compressor Air Hose Line 15m 50ft 1/2" BSP PCL 3 | eBay

HEAVY DUTYOil Resistant Air Hose/Line. It is also Oil Resistant! Made From A High Quality Blend Of Flexible Oil Resistant Rubber & PVC. And Its Material Bag. PROFESSIONAL QUALITY. With 1/2" BSPT male Threaded fitting either end.

www.ebay.co.uk

 

[8ob]

I also have one of those 10/20 gallon pressure pots. Any suggestions for improving it? @brightspark might give me some tips here.
Almost ready to sandblast and paint my trailer - got to do it before winter sets in. Will be blasting outside - assuming we get some dry weather that is

Yes, weigh it in. A lot of time and buggerance getting a home sandblast set up working properly, as a one off its going to be cheaper and easier to get it done professionally.

Bob

 

[fizzy]

Yes, weight it in. A lot of time and buggerance getting a home sandblast set up working properly, as a one off its going to be cheaper and easier to get it done professionally.

Bob

I have used a similar setup before. It does work after a fashion.
Main problem is the metering valve I think. I am sure Brightspark built his own.
Lot of faffing about involved and as professionals charge by the hour no thanks.
I have a ton of glass grit on a pallet somewhere in my warehouse anyway.

 

[MetalMonkey]

I'd suggest 3/4. Keep an eye on ebay for some Norgren or similar.
Hose - I like alfagomma 185. These guys are good

 

[Dcal]

It's been asked and answered loads of times on here.
Thread below is old, but covers most of the mods worth having.
The 10 gal pressure pots can be made into an awesome tool with a few mods.
A lathe and a welder is all you need to make a metering valve.

grit valves for cheap pots

using ball valves to meter the grit is a bit hit and miss and prone to regular blockages :(namely because of its design and iregular grit size it only takes one larger particle to end up in the orifice and everything stops . even the slightest of moisture kills it off . making a flat sand valve...

www.mig-welding.co.uk

 

[fizzy]

It's been asked and answered loads of times on here.
Thread below is old, but covers most of the mods worth having.
The 10 gal pressure pots can be made into an awesome tool with a few mods.
A lathe and a welder is all you need to make a metering valve.

grit valves for cheap pots

using ball valves to meter the grit is a bit hit and miss and prone to regular blockages :(namely because of its design and iregular grit size it only takes one larger particle to end up in the orifice and everything stops . even the slightest of moisture kills it off . making a flat sand valve...

www.mig-welding.co.uk

Cheers I knew someone had posted something interesting about it

 

[bricol]

Yes, weigh it in. A lot of time and buggerance getting a home sandblast set up working properly, as a one off its going to be cheaper and easier to get it done professionally.

Bob

Yep - I found a couple of local guys - I've mentioned here before how one wondered if he was charging me too much money as it only took him five minutes - pointed out I was paying for a job that if I did it would take me longer, involve me doing a lot of cleaning up, use a lot of energy and my time - so I considered it extremely good value . . . although I wasn't volunteering to pay him any more money

 

[brightspark]

Yes, weigh it in. A lot of time and buggerance getting a home sandblast set up working properly, as a one off its going to be cheaper and easier to get it done professionally.

Bob

the only thing needed to make them work efficiently is a quality media regulator valve and a 3.0mm carbide blast nozzle .a 28cfm comp will run nicely at 90psi using a half inch water seperator and preferably a 15mm bore hose feeding it . i sive the media fill the pot and it will run all day long without even touching the media valve once regulated the only thing i use is a secondary tank next to the pot that catches most of the water and cools the air before going in to the water seperator on the pot . i leave the drain on it slightly open and any water just blasts out of it leaving the air perfectly dry going down the blast pipe

 

[8ob]

the only thing needed to make them work efficiently is a quality media regulator valve and a 3.0mm carbide blast nozzle .a 28cfm comp will run nicely at 90psi using a half inch water seperator and preferably a 15mm bore hose feeding it

I must be doing something very wrong BS, I have a two tool 125cfm road tow compressor and a Clemco pot and that seems very slow. The guy I use for my blasting has a monster road tow and an eight bag pot, he uses a fraction of the media and covers four time the ground I do in a fraction of the time, he reckons its because I dont have a big enough compressor. Cant see how 28 cfm can be any good


Bob

 

[brightspark]

I must be doing something very wrong BS, I have a two tool 125cfm road tow compressor and a Clemco pot and that seems very slow. The guy I use for my blasting has a monster road tow and an eight bag pot, he uses a fraction of the media and covers four time the ground I do in half the time, he reckons its because I dont have a big enough compressor.

Bob

what size jet are you using on it i have a 90cfm road tow comp and the biggest jet for it is 6,0mm @ 90 psi ideal for car wheels real quick but not realy eficient for bigish flat aerias

 

[8ob]

what size jet are you using on it i have a 90cfm road tow comp and the biggest jet for it is 6,0mm @ 90 psi ideal for car wheels real quick but not realy eficient for bigish flat aerias

At a guess I would say about 15mm

Bob

 

[brightspark]

At a guess I would say about 15mm

Bob

a 15mm jet i bet that wouldnt run at 90psi in use .if it was more like a 3/8th for that size comp

 

[Dcal]

I blast far more stuff than I really need to, because it so quick and easy with a well setup blast pot and cabinet.

It's easy to blast stuff quickly with a huge nozzle and compressor but it's just as easy to distroy what you are blasting.
Big isn't always best unless you are blasting heavy structural steel work and in that case you can't beat CFM.

 

[julianf]

Do different medias need different total CFM?

Not that I can afford it, but I really like the idea of stainless shot in a cabinet. It seems (maybe I'm wrong, I don't know?) that you buy it, and then don't really have to consider it again?

 

[fizzy]

I must be doing something very wrong BS, I have a two tool 125cfm road tow compressor and a Clemco pot and that seems very slow. The guy I use for my blasting has a monster road tow and an eight bag pot, he uses a fraction of the media and covers four time the ground I do in a fraction of the time, he reckons its because I dont have a big enough compressor. Cant see how 28 cfm can be any good


Bob

I once had a pro shot blast place do me a favour job. A pair of heavy drive gates. He promised me a favour so I called it in. He was cursing. Took hours and used loads of grit because of all the fiddly bits. More gaps than steel.
My trailer frame would pretty much be the same.

 

[brightspark]

I once had a pro shot blast place do me a favour job. A pair of heavy drive gates. He promised me a favour so I called it in. He was cursing. Took hours and used loads of grit because of all the fiddly bits. More gaps than steel.
My trailer frame would pretty much be the same.

i wouldnt do gates for anyone when i used to do car wheels for folk for profit .there more miss than hit with the shot and a waste of time

 

[not done it yet]

At the start of this thread, my first thought was that 30 CFM `and 7.5HP were not particularly compatible, especially from that source. Do you need 30 CFM, or will less than that suffice?

 

[brightspark]

At the start of this thread, my first thought was that 30 CFM `and 7.5HP were not particularly compatible, especially from that source. Do you need 30 CFM, or will less than that suffice?

a couple of 14cfm pumps conected together will be ok a 14cfm on its own is pretty poor petering out of pressure which isnt good as the ratio of air and media alters giving poor cutting power and using more media

 

[ArAKern]

I have a basic DIY setup using the eBay pressure pot and a 12cfm compressor.

From my limited experience:
It is slow but my time is free
As mentioned sieve all media! even new and especially if you are reusing.
No issue with media valves. (need to tune it to the sweet spot for the setup)
Still use the cheap ceramic nozzle they wear but cheap to replace.
As mentioned use decent media JB super fine was recommended to me and is excellent (been left in my pot outside for years and still runs fine I recycle it 3-4 times it becomes dull and not effective but again my time is free.
Run the largest line you can it is CFM not pressure that helps. (60psi still blasts but it is very slow)