Buying blasting kit

[Jonathan Webb]

A post of mine has thrown up the idea of buying sand/grit blasting kit. Mainly to blast mild steel sculptures for painting (and possibly stripping our boat back to gelcoat next winter). This is a garage/garden operation and would only be occasional.

I've searched on the forum, but not found anything helpful yet.

I have an Abac 3hp 11.2cfm 90l compressor, which I believe to be adequate if not the speediest.
Are the cheap blasting pots any good? What's the next step up from the cheapest? (in terms of features etc)
Other than a barrowload of PPE (mask, hood, gauntlets) and dust-containment tarps, what considerations are there? Noise and dust spring to mind.

What sort of media to prep mild steel for priming?
How to calculate how much you need?
Any resources, or good sites with info on small-scale blasting?
Many thanks

 

[optima21]

this is my setup, the first link doesn't work, but its the generic cheap option

http://www.mig-welding.co.uk/forum/threads/my-blasting-setup.76834/#post-1069214

airfed hoods can be used with vaccum cleaners as used blowers (or leaf blowers)

crushed glass media is cheap enough if bought in bulk

http://www.stacey-processing.com/

although it is suposed to be single use, you can re-use it an it gets fine and finer until it just chanegs to dust.

 

[Jonathan Webb]

this is my setup, the first link doesn't work, but its the generic cheap option

http://www.mig-welding.co.uk/forum/threads/my-blasting-setup.76834/#post-1069214

airfed hoods can be used with vaccum cleaners as used blowers (or leaf blowers)

crushed glass media is cheap enough if bought in bulk

http://www.stacey-processing.com/

although it is suposed to be single use, you can re-use it an it gets fine and finer until it just chanegs to dust.

Thanks for that, and your previous comprehensive thread. Very useful info.

 

[gaz1]

you havent looked enough theres some on the forum

http://www.mig-welding.co.uk/forum/threads/bit-of-a-clearout-sale.83341/#post-1188362

http://www.mig-welding.co.uk/forum/threads/air-tools-and-spray-guns.82947/

 

[Jonathan Webb]

you havent looked enough theres some on the forum

http://www.mig-welding.co.uk/forum/threads/bit-of-a-clearout-sale.83341/#post-1188362

http://www.mig-welding.co.uk/forum/threads/air-tools-and-spray-guns.82947/

Most of my search for blasting threw up stuff about cabinets or blasting media for aluminium.I did see the top link though- it's a spot blaster. Too small.

The bottom one is a misc load of gear that may or may not be useful and is collection only, nearly 200 miles away. I have no idea if that blast gun is suitable
Thanks for the links anyway.

 

[gaz1]

theres one on now

 

[james butler]

first thing your going to need is a bigger compressor.
i have a compressor thats 14cfm and its not really enough.
other way around it is a huge accumulator but a bigger compressor would be the best.
i sold my sand blasting cabinet as it was too air hungry.
was cheaper to send it out to be blasted then pay the electric for the compressor to continually run trying to keep up.

 

[Dcal]

The blast cabinet I bought came with a 8mm ceramic nozzle in the gun. That would take a 50 or 60cfm compressor to run flat out!
I changed to a pressure pot and a 3mm nozzle which is more suited to the 3hp compressor I use and is fine for small stuff.
There is also the added advantage that it doesn't wreck thin steel or alloy parts during cleaning.

More air is great but sometimes it's better to spend time doing something rather than spending the time taking it to someone else to do, then waiting for them to do it, then going to collect it and hoping it's ready.
Also not everyone has a local blaster to go to.

 

[Jonathan Webb]

I'm going for this!
(1) What size pot? The bigger, the longer you get between refilling & so less downtime as it pressures up? vs having a great big tub around for the 99% of the time you're not using it. If I went for 10gal/45l would I be topping up every 10 mins, every half hour? Cheers.

(2) I get that the supplied ceramic nozzles wear out quickly and I will want a Tungsten carbide one - will the supplied ones last for this job? Or do I need to get this now - again, do they last minutes, hours or days?

Many thanks

Dcal, waiting to hear costs on the Supafine. Can get glass locally for £10/25kg. When I initially enquired about getting this blasted and zinc-sprayed, they couldn't/wouldn't guarantee no distortion on 3mm steel, so I'm happy to take it gently if slowly.

 

[123hotchef]

My 10 gal pot turned up today so did my tungsten nozzles

 

[brightspark]

I'm going for this!
(1) What size pot? The bigger, the longer you get between refilling & so less downtime as it pressures up? vs having a great big tub around for the 99% of the time you're not using it. If I went for 10gal/45l would I be topping up every 10 mins, every half hour? Cheers.

.

who are u kidding fill up every 10 minutes what are you doing throwing it on its 80 percent air at 90psi for efficiency and 20 percent grit or sand .a 1 and a half bag will last half an hour

 

[123hotchef]

Do u just open the valve on bottom of pot fully.

 

[brightspark]

Do u just open the valve on bottom of pot fully.

no it needs regulating so the minimum of grit or sand flows and gives a good cutting speed . 2 much media slows the velocity down and uses more grit

 

[123hotchef]

no it needs regulating so the minimum of grit or sand flows and gives a good cutting speed . 2 much media slows the velocity down and uses more grit

Great just trial and error then

 

[brightspark]

Great just trial and error then

start off with tank pressurised grit valve closed . then slowly open it with the till it starts stripping paint easily . keep the jet about 3 inch from the work . practice makes perfect

 

[123hotchef]

start off with tank pressurised grit valve closed . then slowly open it with the till it starts stripping paint easily . keep the jet about 3 inch from the work . practice makes perfect

Thanks I'll have a play tomorrow might just ditch the gun and stick the tungsten tip straight into the hose

 

[123hotchef]

Here the nozzles are

 

[Jonathan Webb]

who are u kidding fill up every 10 minutes what are you doing throwing it on its 80 percent air at 90psi for efficiency and 20 percent grit or sand .a 1 and a half bag will last half an hour

No idea mate - that's why I'm asking!!! It wouldn't be the first time someone's suckered into buying a tool that wasn't fit for purpose or just crap - what about the poxy gas bottles that come with little MIGs, how long do they give?
If a 45l pot will hold a whole sack and give me an hour, I'd be happy with that

 

[Jonathan Webb]

My 10 gal pot turned up today so did my tungsten nozzles

What CFM can your compressor run? Mine's rated at about 11 so not the greatest. Which pot did you go for?

 

[brightspark]

one of the biggest problems with most set ups doing open blasting is containing the mess and its preferable to have an air fed blast helmet and a good air supply or use a cabinet with a decent 4 inch woodchip extracta fan and use it with a pressurised pot