Pressure Washer Sandblasting Kit - Wet Abrasive Sandblaster Attachment

posplayr

Senior Member
Joined
May 5, 2018
Posts
792
Location
Tucson
I have been using one of these devices for the last month to sandblast a couple of sets of aluminum wheels. It works well on the soft aluminum but if you have some harder rusty steel it will be good for prep to paint but you will need a rust convertor before top coating. At least this is my initial indication for a 16x8' trailer I need to refurbish. It gets off the bubble up and flaky stuff but deep rust stains will take a lot longer to remove. The rust convertors will easily seal the rust-stained metal and you can paint over that for a very very long lasting coating.

The aluminum gets a nice fine rough surface that powder coat or paint will adhere to very well resulting in a smooth painted finish. Because the steel is harder you will also get a certain amount of surface roughness but probably much less than the softer aluminum. The blasted steel surface is still a great surface to paint over, especially with such large objects as flatbed trailers.

Because the setup can be a bit touchy I will describe what I went through before finally getting this setup to work well. Sorry, no pictures my iPhone died from a lack of a charging connector. I'm going to start working on that as soon as I'm done with this post.


First I have an old Karcher K2400HH (with a Honda 5Hp motor) I bought it around the year 2000 (probably 1998). In 2021, it was leaking pretty bad, and I could not find a replacement pump but I was able to find rebuild parts, so I rebuilt the pump. That helped a lot with the pressure

Model : K 2400 HH (Honda 5.0 hp)

I bought one of the attachments recently (many are virtually identical ). It was marginal at first until I got a few things sorted out.

https://www.amazon.com/gp/product/B086W4TNQC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I started with "play sand" from Home Depot. I don't think the sand is super critical as long as you sift it down to relatively small grains of sand as the larger pebbles will clog the gun and give you fits. Right now I'm using an old window screen and it works fine although I did buy some stainless screen for when the window screen wears out. The 60 lbs bag is just about the right size to 75% fill a 5-gallon bucket. Also, I don't want to lug 90 lbs bags anymore.


https://www.homedepot.com/pep/SAKRE...JzbwSmop3SQaxIjty74aAnvVEALw_wcB&gclsrc=aw.ds

So with the screened sand, clogging essentially disappeared. The big screen is good because even if you are sloppy with pouring the sand out of a bucket to sift into another bucket, the oversized screen keeps anything larger out.

So at this stage, the blaster was hit and miss. There was not enough suction from the gun to pull sand from the bucket. Sometimes the suction would stop with the inevitable pickup hose being plugged with wet sand so no sand-blasting effect.

I kept dealing with the issue, which required constant movement of the stainless pickup in the bucket. Basically, pull the trigger for 10 seconds, and walk back and kick the sand-filled bucket to get the pickup tube back to covered. I probably went through 3-4 60 lbs bags this way and my clothes would get soaked (not the worst thing in 105 deg heat) because my gun nozzle would leak (past the trigger but before the suction tube).

If you bury the pickup too deep and you have low suction the pickup will just plug up and then the greater water pressure will push water back down to the pickup and you have a wet sand plugged pickup.

This was with the the original gun that came with the pressure washer in 1998, so it was old and leaked despite me changing some of the O rings. So I bought one of these and the whole setup works great now.


https://www.amazon.com/gp/product/B07YC2QFJ9/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I bought a set of used Polaris Ranger wheels for my new-to-me Gravely side-by-side. I was able to sandblast 70-80% of the 4 wheels with one bag of sand in less than an hour. This was my second pass, whereas the first pass was with the old gun and all the previously described issues. I took twice as much time and sand and did not get nearly as much factory powder coating off with the old gun and weak pickup vacuum.

At this point, after buying a 100-gallon compressor, and a harbor freight blasting cabinet (with an assortment of DIY upgrades) I wonder why I ever need to use the compressed air blast cabinet and all the associated dust?

The worst thing about the pressure washer sandblasting is I feel like I just came back from the beach when I get done. :d3:
 
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I've been thinking about this for a while, thanks for your review!


Do you do anything to try and reclaim any of the sand?
I've seen people blast over a tarp, or a concrete driveway and try to catch some of the media for reuse.
 
I've been thinking about this for a while, thanks for your review!


Do you do anything to try and reclaim any of the sand?
I've seen people blast over a tarp, or a concrete driveway and try to catch some of the media for reuse.


Reclaiming the sand would not be that hard. My front yard is large on 1/2 acre and we have a lot of sandy ground in Tuscon so it just mixes in to the ground.

If we were on a lot with neighbors 10 feet away and grassy side yards I would try and capture most of the sand. A large Harbor freight tarp put up with a backstop would catch most of it but then you have to get it dried out to reuse.
They just raised the price for HD play sand to about $7 a bag but for $25 I can get 4 bags which is quite a bit of blasting.

Right now I'm pricing a more powerful power washer. The flow rate is the same as the one I have but the pressure and engine size is about 30% more so overall i would expect to save money on water because it will but better and faster. The Honda motor in my Kaucher has been great. It can sit for months in the sun and it starts with one or two plus on choke. Once it has been running it starts in a single pull. The one I have is a GC160 cc engine which seems to be rated at 5.0 hp (it may be lower like 4.4 hp) and the 3300 Dewalt branded motor is a Honda GCV 200 (commercial) 208 cc with 5.8 hp. Teh cc's are about 30% higher.

Amazon.com


There is silica sand which is harder but $20 per 100 lbs ($0.20 per pound). The play sand is $6.5 per 60 lbs ($0.11 per pound) so it is twice the price but if you use a tarp and with the saving in water and gas it might be well worth the effort.

100 lb. #20 Silica Sand

If you have a really big job (like a large boat) you can go to 4200 psi pressure.

I would not recommend siphoning right from an open bag, it needs to be sifted. Depending on what you will resurface with, you don't need clean bare metal when using Por -15, for example.

 
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I forgot people have to pay for water.
I just checked my pressure washer, it's a GC190 rated at 5.2 hp.


Good point on the cost per pound of play sand.
 
I forgot people have to pay for water.
I just checked my pressure washer, it's a GC190 rated at 5.2 hp.


Good point on the cost per pound of play sand.


For aluminum, the 2400 psi is enough, but the underside of my flatbed trailer may have never been painted and it has 30 years of rust so retiring the Kaucher after 35 years of service seems appropriate and not at all spendthrift (even though it works fine).
 
I did receive the Dewalt sprayer and it is a definite upgrade to the 2600 PSI Kaucher. The more psi the better. The main thing is that with higher pressure, you get better suction, and so it will feed sand more reliably. Stripping rust and paint is much more effective with sand coming out the nozzle.

Right now I'm pricing a more powerful power washer. The flow rate is the same as the one I have but the pressure and engine size is about 30% more so overall i would expect to save money on water because it will but better and faster. The Honda motor in my Kaucher has been great. It can sit for months in the sun and it starts with one or two plus on choke. Once it has been running it starts in a single pull. The one I have is a GC160 cc engine which seems to be rated at 5.0 hp (it may be lower like 4.4 hp) and the 3300 Dewalt branded motor is a Honda GCV 200 (commercial) 208 cc with 5.8 hp. Teh cc's are about 30% higher.

Amazon.com
 

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