Great performance/value for a realistic budget

[shed or dead]

Hi, I'm new here, only registered because I read the sandblasting tutorial and wish to thank the author for the great advice and share how I modified the same equipment to produce brilliant results on a budget. I'm not selling anything, just want to help other metalwork enthusiasts like myself.

I opted for:
Clarke 14cfm compressor SE16C150 (prized possession
10 gallon pressurised blast pot (ebay, orange one, great but go for 20 gallon)
Clarke SB Gritblast gun
Assorted airlines and fittings.
Hodge Clemco JBlast supa (expendable abrasive, but use it again and again)

So pretty much what's covered in the tutorial on this site.

From the compressor, split the air feed to 2 airlines.
Remove the reservoir/grit holder from the clarke grit gun.
From the blast pot, remove the nut which holds the ceramic nozzle, screw the plumbing valve (outlet on the rubber hose of the blast pot) into the grit gun where the reservoir was (blast pot becomes large pressurised reservoir).

So we now have a 6mm long life steel nozzle capable of delivering large grain abrasive without clogging. The additional benefit comes from an extra 150psi (up to) of air pressure at the nozzle, with a trigger control (still a 2 handed job as the valve from the blast pot is independent of the trigger).

Pictures and samples of work to follow. As an example, I blasted an axle from a lightweight Landrover coated in mud, oil, waxoyl, paint. With no exaggeration, 3 seconds blasting resulted in clean bare metal with a good key for painting. The area blasted in that time was slightly larger than the lid of a lucozade bottle (would have kept going but just an experiment without ventilation). Anyway, I will borrow a camera and post pics soon. Doing a Landrover rebuild so lot's of potential examples.

Thanks for an informative site.

 

[rtbcomp]

Welcome to the forum.

That's a good idea, but you'll find the "long life hardened steel nozzle" is Clarkes interpretation of "long life"! i.e. it wont last that long at all.

If you look in the links section under "Grit Blasting" there is a firm listed that supplies suction guns which will take a tungsten carbide tip, that may be a better bet than the Clarke one.

Not quite sure how the trigger still works, I have a similar blast gun with a suction tube rather than a grit container and the trigger just works the compressed air.

 

[shed or dead]

the trigger just works the compressed air.

Spot on. Open the valve from the blast pot and the flow of grit is visible like water from a tap due to the large 6mm nozzle. Take aim and press the trigger to introduce the high pressure air behind the flow of grit.

As you say, the nozzle life may not be long, I'll have to wait and see. I just needed to proceed with what was available to me. This will definitely be a case of continuous improvement.

Next will be a large home made blast cabinet. My current setup of tarpaulin, gaffa tape and perspex is growing tiresome. Any advice is appreciated.

Still working on those pictures.

Thanks for the kind welcome, time I retire to the shed for a while!

 

[rtbcomp]

So presumably you still have the compressed air pipe to the gun as well as the pipe supplying the grit.

Do you have the bypass valve on the pot closed?

 

[shed or dead]

Yes, the compressed air pipe goes into the gun as well as the grit pipe. I leave the bypass pipe open to assist the flow as the grit pipe is around 2m long and I was concerned that a good feed might not be maintained otherwise.

No more blasting today as I've blown a hole in the side of the grit supply valve on the gun end. The hole is directly behind the valve handle (round the back). Only running a max pressure of 80 psi to the pot. Plumbers merchant tomorrow.

 

[rtbcomp]

I've been thinking about this method for a while.

The way I was going to do it was:-

keep the bypass valve closed
open the bottom valve fully open
discard the nozzle valve
regulate the flow of grit with a pressure regulator feeding the pot (10psi?)
have a seperate regulator for the gun (80 -90 psi?)

When you're resting just point the gun into a bucket to collect the grit. When finished cut the air supply to the pot and use the gun as an air duster to clean the workpiece.

Because the grit is moving much more slowly in the pipe there will be hardly any wear so you can use narrower bore pipe with a thinner wall. This will make manipulating the gun easier.

The downside would be getting into confined spaces with the gun.

 

[shed or dead]

picture of the blown ball valve next to the new one, certainly looks a bit more serious. $4.50 from the local plumbers merchant (keyboard has no pound sign?)

Other assorted shed pictures. The 'T' air splitter on the pressure pot was only $2.98+vat from machine mart, I think they probably made a mistake but I was pleased.

The engine crane holds work so it can spin inside the folded and taped tarp. It's all a bit gaffa tape intensive at the moment.

After all that I forgot to photo the gun setup but I'll get back to it tomorrow.

I was thinking of using a spring to close the grit valve and an old clutch cable to foot pedal to operate, or perhaps connect valve to trigger by some simple means (and strong hands)? Could become permanent if the current parts survive a few months work.

 

[shed or dead]

I must get my girlfriend to take some better pics, I don't invest in non-workshop technology and my hands only hold still when welding.

 

[rtbcomp]

That valve damage is typical. I've done away with mine altogether.

To increase it's life, it must be either fully open of fully closed, regulate the flow of grit with the bottom valve.