Perfect blasting setup?

[gasket999]

Hi folks. There are dozens of threads in here regarding blasting set-ups and I have read the bulk of them.

That being said, I’m hoping to compile a lot of them into a single build thread - so please bear with me.

so... I’m on a domestic electricity supply and so far I have a nice Fiac 14CFM 3hp belt-driven compressor at 14CFM (not FAD), filling a 150 litre tank. Being a bit on the small side, I’m topping this up with a second 14CFM pump and motor that will kick in at a lower pressure.

Both air supplies will be plumbed into 22mm copper pipe, via a PCL 100 whip hose and will eventually be displacing 28CFM (somewhere around 18-20CFM FAD), feeding a generic Chinese blast cabinet like this:

Now. There is an excellent video series on a YouTube channel called Ray’s garage, where working with the Tacoma company - he fits the full suite of upgrades to this type of cabinet (sold in the US by Harbor Freight):

The full kit he fits includes:

1. A quick change real glass kit
2. A set of internal baffles which stop the build-up of media
3. A set of better lamps (iridescent -so keeping the box dry)
4. A better assembly method with lots of sealant and headless “rivet-screws”
5. A relocated extractor position, a baffle box and a few covers that work with a vacuum flow meter and a simple adjustable valve for the shop vac pressure
6. The removal of the ribbed floor plate and making the mesh grate smaller and lower to enlarge the volume inside.
7. And then the gun setup: this includes a special funnel that replaces the trap door hatch, onto which a metering valve is fitted, plus a foot control and air regulator and a trigger-less gun.

phew! Anyway, with all of the above fitted it ends up being quite a good machine - uses minimal media, which is fast to change and offers good visibility.

so, onto me. I contacted the Tacoma company and - while their product seem excellent, the prices with shipping are a bit out of my reach.

so, plan B: I can make the parts to do items 1-6 myself, with minimal effort, no worries there. Then we’re onto the gun setup (number 7 above). A quick google brought up an equivalent set (though inevitably cheap Chinese made) sold by sandblasters.co.uk for £159

So: £189 for the cabinet, £159 for the metering valve/gun/pedal setup and a bit of time and effort to fold-up the internal baffles and shrouds, change the lights, mod the glass and vacuum system coupled with better assembly techniques and I’ll have a setup very similar to the Tacoma company setup.

But, it doesn’t stop there. I’ll be fitting a dust-buddy type cyclone extractor to a sealed bucket before the vac for about £18, like this:

then - I revisit the gun... and my questions start:

1) would it be best, given my small setup to stick with the suction setup above or instead move to useing an eBay pressure pot like this?

Obviously, I’d be binning the standard valve and would use the 3mm tungsten nozzle shovelled into the pipe with a jubilee clamp.

2) if so, is it best to go for 10litres or 20?
3) if I do go for a pot, and wish to keep the foot pedal - is that possible.
4) again if I go for the pot, where would the metering valve come in? Does it go on the bottom of the pot - and if so, is it a case of letting the media build up into the cabinet and emptying it regularly or is there a way of recirculating it?
5) again with the pot, is the t-shaped off the shelf metering valve still a good idea, or would I be better following brightspark’s lovely clemco-copy flat-valve? (I do have a small lathe and can cast aluminium too).

... so, a million questions - but hopefully should see the best home blast cabinet I can for somewhere between £400 and £500 all done.

• I’d like to blast everything from rusty Land Rover steel parts, to delicate aluminium and brass.
• Id like to be able to change the media regularly from j-blast to glass bead.
• I will sieve the media, but am looking for a reliable little setup with a 3mm nozzle (think I’ll need to make an adaptor for the Sandblaster.co.uk gin if I’m not using the pot).

Any tips are very welcome. When it’s done I’ll do another build thread like I did for my (old) compressor build.

thank you for bearing with me!

 

[Dcal]

Hi @gasket999

I've a similar set up and it works a treat.
You can never have enough extraction, a workshop dust extractor for wood working is a better option than a vacuum. Putting it through a cyclone will help remove dust going into the extractor (it what I do)
To answer your questions

1. Dump the suction gun and use a blast pot.

2. If you are going to change media often, go for the 10gal pot.
Unless you have a huge compressor and are blasting a lot there is no real need, plus the break to fill the pot will be welcome and will give the compressors a break.
I installed a big bung to make it easier to change the media.

3. It's easy to fit a foot pedal, just rig it so that it turns the air on going into the pot (as long as the valve can flow the air)

4. Don't go to the bother of trying to get the grit to recycle back into the pot, it's not easy and even if it was you will be getting blockages from the paint flecks and grit getting into the system. Better to stop, empty the cabinet and sieve the grit back into the blast pot.

5. The standard metering valves are useless, make, or buy a proper one. Brightsparks' is a tried and tested option.
I made a variation that has worked flawlessly since I installed it.(details in the link below)

@brightspark hope it's OK to resurrect and hijack your thread?
Your work on the grit valve was certainty the inspiration for me having a go at this.

Here's my version so far.
Started messing about with it after my earlier post in this thread.

Dimensions, as always, are based on what's in the scrap pile.
I remembered I had a bit of 72mm tie-bar kicking about so dug it out to see what it's like to cut and machine.
They are usually a similar grade to re-bar but this is old (70 or 80 years?) so it's anybody's guess.
It seems fine to work with.

View attachment 187665

Sliced a couple of bits off with the band saw

View attachment 187666

View attachment 187667
Bit of a variation on the design.
I don't know if it's necessary, or if it will improvement it, or if it will even work but I machined a funnel into the lower part of the valve to see if it improves the flow of grit.
I'm also going to see if I can make it in 2 thicker bits and leave out the middle spacer.

View attachment 187669

Starting to get to grips with this 4 jaw clocking malarkey.
Next to no step when I turned the blank around in the chuck to machine the other end.

View attachment 187671

I went for a 10mm orifice for the grit, but that seems big so might make a smaller one.

View attachment 187670

That's it for now, another evening's messing should see if the prototype works.

ed it.

 

[MetalMonkey]

I built my own using the same metering valve and foot pedal in your first option - but ponied up for a BNP gun with a tungsten carbide nozzle which lasts infinitely longer. It has worked great and doesn't block, polar opposite to the cheap suction tube ones.

You can get much the same setup ready built with a dust extractor from the usual suspects on ebay - generic Chinese part number SBC420 or SBC990. No idea how good the dust extractor is on them. For mine I used a s/h Clarke wood dust extractor and piped the outlet outside. I plan to make a cyclone unit for it to help recycle more media and make the extractor last longer, but not got around to it yet.

I've not tired the pressure pot style in a cabinet, but what turned me off is having to stop to refill. Some of the more professional ones have a special valve at the top that allows you to refill the pot from the collector on the cabinet - but these were all well outside my budget.

 

[brightspark]

a pot that can take over 30 kg will last a good while and do everything you want without having to refill all the time .regulated properly they don't use much media I use a quick release lid and is only a few minute job to refill after sieving the crap out of the media

 

[Munkul]

I think you've got it covered. Cheap cabinet, pressure pot, good extraction, quick change glass, and lighting.

 

[brightspark]

keep the suction gun as well as the blast pot there good for cleaning small parts without blasting hell out of them I use my guyson lookalike gun sometimes just using sand . its good on ally parts and light rust without damage

 

[cheb]

I took a bleed off my cabinet's pressure regulator and poked it into the extraction duct. Doesn't used much air and keeps the dust down a treat. There's a picture on here somwhere.

 

[gasket999]

Brilliant advice - thank you guys.

I will keep this thread up to date with progress and the build/results. Think it will take a couple of months start to finish (paydays to fund it rather than the work involved).

But... the first (and most expensive) step looks sorted. I’ve ordered a new pump for my big 3hp 150 litre compressor - coming from Germany in a week. And I’ve just ordered a smaller 100litre 3hp compressor too. Both belt driven.

Will post some pics tomorrow.

 

[gasket999]

Just one photo.

the black compressor I picked up today - second hand, but perfect working order. its a rebadged Nu Air (Italian) unit.

the red one I bought a couple of weeks ago - beautiful condition and barely used... albeit with a knackered pump due to user error, and thanks to Brightspark’s tip on identifying the pump, I have a new OEM one coming in from Germany.

Each is 3hp/14CFM.

that’ll be it for a couple of weeks - next up will be plumbing.

 

[gasket999]

Just a quick query guys:

Im toying with refurbishing both compressors and selling them in order to buy a brand new matched pair. The reasons for this are storage and parts availability (the fiac prices and difficulty in getting them as a private buyer has annoyed me to some degree) and the ability to buy spares from a single source . Also the price I paid for them was a touch ridiculous (cheap) and, even factoring-in the new pump from Germany - I’d have a fair chunk of equity/profit (around £400 after my costs, believe it or not) in them if I were to sell them both on - easily enough to buy one unit new for ‘free’. With new, I can service them by the book and also swap the lead-and-lag over periodically.

As such, could I ask about tank sizes? My thought is that as blasting will make the tank size irrelevant, that a pair of small 50L compressors - but each 14CFM and belt driven with a 3hp motor, will take up much less space and with a rack I can stack them on bolt less shelving - which would also make it easy to form a well ventilated enclosure to deaden some of the noise.

I do some paint spraying too, but figure I’d still have 100L in the two tanks and 10L in the pipework before one of the compressors has to kick in.

I confess, I’ve never really understood the need for a massive tank as surely it’d still empty in seconds when using hungry tools.

... that just leaves the choice of:

1. 2x Cheap clarke 50l belt drive boxers (£680 less the equity) Chinese but easy/cheap to buy parts from Clarke - know this from last time
2. 2x blue 50L Clarke XEP15/50s (£900 less the equity) probably Chinese but easy/cheap parts
3. 2x 50L SIP TN3/50-SRBs - rebranded quality Italian NUAirs - £900 less the equity - far easier to buy parts than the FIAC
4. 2x cheapo 90L Burisch BT-390Ts - like the beloved Wolf one that’s out of stock everywhere - £550 less the equity. Not sure on parts, suppose this is only good as long as GTAir are in business.

...but, if a large tank is genuinely more useful then I’ll keep one of the ones I have - sell the other and buy a matching one. Probably selling the big Sealey and buying another matching 100L SIP/Nuair one for around £450 - less the equity in the Sealey.

Just a random thought - but I thought I’d get some good advice here.

 

[Wedg1e]

As far as I've seen over the years, whatever the badging, very many compressors use the same Italian pumps made by ABAC; there is a UK spares supplier -

https://www.airsupplies.co.uk/air-c...s-and-spares/abac-compressor-spares-and-parts

I have a 100L 3HP SIP and a 270L 3-phase Clarke (still for sale ) and my son-in-law has a 150L BluePoint and they all have ABAC pumps fitted.

I run my Guyson (suction) cabinet from the SIP and I've known it run for literally hours without stopping, on a big blasting session (time just passes ) - it never drops below 80psi and will still shift light ferrous corrosion, alloy oxidation and thin paint at that.
The SIP was second-hand when I got it given about 18/19 years ago and it's never had more than an oil change and filter clean (and tank drain, of course).

 

[gasket999]

Hi folks. Lockdown had stopped play in the main, but next weekend I should be able to update in the compressor situation - the new pump is fitted and oiled up: just waiting on some cable to run an extension.

can I ask if anyone has the generic Machine Mart/Harbor Freight/ eBay blast cabinet S per the pic in my original thread? I’m looking for a couple of measurements:

1) floor to the bottom lip of the door (ie I’d like the door to swing open over the top of my bench to the right of the cabinet)

2) bottom lip of the door to the top of the cabinet.

I’m remaking my benches and running new power conduit while I have time on my hands: but waiting till next payday for the blaster itself.

thanks!

 

[gasket999]

Bit of an update: the 220 litre blast cabinet is winging its way over from Germany. I'd been watching the prices on eBay as they started to creep up, then found a deal from a German supplier on Manomano - £175.95 delivered, which I was pretty chuffed with - buy the time I resell all the bits I don't need, it'll work out quite cheap.


I've traded the compressors above for one new (effectively free) 14cfm/100l belt drive unit and am including a second port in my plumbed, fixed airline, next to a 16a socket to let me add a second matching compressor when I'm ready.

The first compressor will be soundproofed in a ventilated enclosure and can be used all day long - the second will be freestanding and I only want to use that one occasionally (I live in a quiet residential area).

So my ideal is to have a setup that will do little bits in the cabinet using just the one compressor, with the second to add the oomph when I need to shift heavy rust/larger areas.

To that end - I'm taking all the advice above... and I'm going to run both options into the cabinet: a metering valve/Clemco BNP-knockoff gun for day to day bits and a blasting pot for the heavier stuff (god bless cheap Chinese imports).

I think I'm OK with the metering valve option with all the info from US YouTube (thanks for the reassurance @MetalMonkey - can I ask what size compressor and nozzle you're running and how long you can use it for? I understand this option is typically run at lower pressure)

Could I also fire a couple of questions to @brightspark or @Dcal?

I've been through quite a lot of your threads on flat sand valves and was sure you could point me in the right direction.

I'm going to order a small pressure pot - one of the 10-gallon ones (there's a place where I plan to wall-mount it and a 20-gallon one wouldn't fit) and make the relevant changes.

1) Am I right in thinking I can just buy the 1/2" Junior Flat Sand Valve from CenturyWise and screw this into the bottom of a eBay pot and replumb it? I'm guessing that the redundant ball valve on the bottom is 1/2BSP.

2) The common info from the forum is that a 14CFM (9-10CFM FAD) compressor will just-about run a 3mm nozzle. In my case that means I could use it until the compressor starts to lag behind and then kick-in the second compressor. But... I've found two suppliers of 2.0mm and 2.5mm nozzles, one is very close to my house - a supplier for etching headstones for funerals, rather morbidly. They sell a carbide nozzle designed to go into the end of a 1/2ID hose with a jubilee clamp. Given that I would ideally like to run the blast cabinet off the one compressor day-to-day, would I be better with a 2.5mm nozzle from them, rather than stretching the air supply to try for 3mm? I will be blasting lots of smaller, very rusty steel parts in the main and occasionally doing some bead blasting on larger aluminium gearbox casings. If the ACE/Blastitclean people are to be believed that at 2.5mm, I should be able to maintain near 100PSI with a 3hp compressor and this nozzle - though they do say that this should be used for grit under 500microns and I'd be expecting the 'fan' of blast to be quite narrow - hopefully not unusably so.

 

[minimutly]

The mixer? Valve is the most important bit in my opinion. My "cheap ebay pot" needs constant shaking to maintain grit flow, I think it was sold to use fine glass beads and probably worked fine like this (I bought it used but like new).
The plan is to make up a version of @brightspark valve, which should transform it. I must admit I did contemplate making a vibration motor and fitting it to the pot.
Now I've got the inverter tested on my silent running atlas copco vtwin compressor all I need to do is sort out a control circuit for it - don't want to go back to the blowoff valve going off every 3 minutes like it used to....
Sorry for the hijack...

 

[MetalMonkey]

(thanks for the reassurance @MetalMonkey - can I ask what size compressor and nozzle you're running and how long you can use it for? I understand this option is typically run at lower pressure)

I have two compressors, an HW16 http://www.aiedirect.co.uk/page9.html with 100L tank which gives 10-16 cmf and a Sealey generic belt drive 150L which claims 14cfm but gives closer 10. I can run either or both of the compressors and utilise the full 250L of capacity by opening or closing some ball valves. I plan to de-rate the Sealey further by slowing it down as it runs its nuts off to try and get the cfm and now I have two I would prefer it to run cooler and quieter.

I use the smallest boron carbide nozzle that they do - I think it is a 6mm see here - https://www.ebay.co.uk/itm/clemco-B...n-div-nozzle-types-sandblasting-/352195117405 in fact I'm pretty sure this is the outfit I got the gun from. I think the specs on it require something ridiculous like 28cfm, but in practice I have found it works fine at far less. I wouldn't go bigger though. I usually run around 50 - 80 psi but it functions probably down to about 30 if you want a really light touch.

In reality I can run my cabinet for a short period just on the reserve if I need to blast a couple of small bolts or a bracket or something, the Sealey will run it for a short while on its own despite being underpowered, but if I have a lot of blasting to do I just switch them both on and I can go all day or until I'm bored..

I don't try and blast wheels or large chassis pieces anymore - you really need a serious blast pot setup for that and there is a chap a few miles away who blasts lorry chassis with a massive diesel compressor and charges a very reasonable rate, so it isn't worth the time, effort and electricity to try and do it myself. However, he will blast right through anything thin. For anything I can fit in the cabinet or that needs a more delicate approach you can't beat the convenience of having a blast cabinet ready to go.

Good dust extraction and ample light along with the metering valve/foot pedal setup totally transformed cabinet blasting for me.

 

[minimutly]

Foot valve on ebay search then...

 

[MetalMonkey]

Foot valve on ebay search then...

You only need a foot valve if your blast gun doesn't have a trigger, which the clemco guns don't...

 

[minimutly]

You only need a foot valve if your blast gun doesn't have a trigger, which the clemco guns don't...

Foot valve for the (bloomin big) blasting cabinet - stainless steel home made creation from some college somewhere, it came set up as an aquablasing setup - the nozzle is still in there, but I couldn't be faffing about with water in the workshop. Maybe one day I'll build an extension and put it in there, but I know very little about these things to be honest.

 

[gasket999]

Just found a 3mm boron carbide nozzle for the BNP gun - seems to be the smallest one made. That should mean that the gun could run at around 70psi from the single compressor for lighter bits.


Yep a foot pedal and a cabinet-mounted regulator is on the shopping list too.

thanks MetalMonkey - that’s really helpful.