Discussion DIY Wet Blaster

I removed the air supply. I got enough turbulence running a firefighting pump through a 6 or 8mm hole in a washer inside a hose fitting. The air certainly helps in kiffsta's machine, though.

 

When I say I blast at 45-60 psi, I have a separate 3 phase pump bringing the water in, my air is at 45-50 psi

the nozzle brings the air and the water together

 

Watch you pressure , too high and you will pock mark the alloy , slow and steady on a lower pressure you yield shinier and smoother results

 

Looks like it is working pretty well. Do heed kiffsta's advice. Some of those parts may have a coarse casting or corrosion pits, it is visible that is the case in your parts, but different material will respond differently.

 

I thought I might give you my tips and tricks for good blasting :

Too much pressure can harm the alloy.

Grease seems to repel the blast media , so spend some time cleaning your parts , makes life heaps easier and a quicker job.

Don’t focus on that spot that won’t come off , you can damage the alloy around it, when I do cases with lots of chain, lube, grease etc , I use some degreaser first to loosen it , I also have a pick that I use to get into those hard to get places and gently break it up.

The age of the alloy and composition of the alloy need to be respected , ie if you are blasting older parts from the 60’s and older , set your regulator for your air flow on a much lower setting or you will blow a hole in it

as a guide
Modern to 1987 - 50- 60 psi
1986- 1977 - 45-55 psi
1976- 1960 - 40 -50psi
Any thing older , Start at 40 psi and see how it comes up , you can always increase

On older alloys , do a test patch that isn’t visable first

Your media to water ratio is key , I aim for between 20-25%, the easy way to test is to find a 4l plastic bottle that is clear ,cut a 3cm hole on one side near the top, spray your gun into the plastic bottle until it overflows at the top , let it all settle and you should see the concentration of your media , if my media settles and I have 3-4 cms of media in the bottom of the bottle , then I am pretty good.

Clean water will yield better results.

if the part you are cleaning has pits from water and / or bad storage be very careful blasting it as the high pressure water and media can make it a lot worse.

gasket material repels the blast media , get a gasket scraper and get as much off as you can.

different grades of media will yield different finishes , I use ah, ad and c grade media from potters , ah is the finest and gives a shinier finish , but doesn’t sink in the water sump as well as the other 2 , ad is my go to bead , great finish. Avoid c bead unless you are doing industrial Cleaning of steel , it is too abrasive for alloy and pits it

be carefull on cylinder heads where there is putting , the blast media can make it worse. Think of 3 stroke heads with det marks

Be wary of parts ( swingarms, fork legs etc) that are anodized or certain parts with that ultra hard clear coat , no point trying to blast it off, even at higher pressures, most anodizers will have a caustic tank, pay them $20 to dip the parts in their tank and then vapour blast to get the nice finish.

don’t blast cases and parts with bearings in there , the media gets stuck in there and you cant get it out. Better to remove your bearings. Invest in a blind bearing puller , honestly it makes life so much easier.

always clean your blasted parts in fresh water and air hose dry , water marks can be a pain to get off if your water is dirty.

dont leave a recently cleaned part of your cabinet overnight or for long periods , it will draw on the water from your sump and will end up with a bad finish.

Wet blasting is not a paint stripping process, buy a 4l tin of diggers industrial paint stripper and remove as much paint as you can, if you try and blast the paint off , it just dirties your water and can damage your pump . Paint stripped is your friend , but watch skin contact , it burns like a mother fucker , also don’t put your hands in the blasting gloves with paint stripper , you can get a warm and fuzzy feeling followed by an emergency dash to a sink to wash it , speaking from experience here.

sometimes it is better to sandblast to remove paint and powder coat , than to wet blast , use the sandblast to get the paint off , then wet blast to achieve the finish , I do this a lot on finned heads on 2 stroke dirt bikes.

blasting steel and cast iron will clean up, but it will flash rust, I use wd40 or similar on barrels after I have blasted them to stop the flash rust. You can buy a rust inhibitor for your sump water , it works okay , but anything with an iron content will still flash rust.

be wary of blasting parts like carbs and master cylinders where there are tiny passages , the blast media will get stuck and ruin your part , better to remove pistons and seals from master cylinders.


You can use your blasting cabinet for other fun things such as etching glass , make a mask from thicker vinyl and attach it to a sheet of glass then blast in the gaps , it will etch a pattern.

You can blast other metals such as copper and brass , but as they are softer,
You need to adjust your pressures , I have cleaned up brass plaques from graves for customers , they came up really well for something that was exposed to the weather for 30 years.

I’m sure there is heaps more , but that is all I can think of now , good luck with it .