Has anyone tried using a pressure blaster to remove carbon off the back of the valves? I put together the standard setup using the siphon feed Harbor Freight portable media blaster (http://www.harborfreight.com/portabl...kit-37025.html), but it just not working for me. I get a couple of grains of sand every once in awhile, and is taking hours. What about using a pressurized blaster like this http://www.harborfreight.com/110-lb-...696-10377.html. It is more expensive, but if it works it would be worth it. And useful for other jobs.

 

Cant help you with the hardware selection but you mention "grains of sand" in your post. The standard media for cleaning the valves is walnut shells not sand.

There are numerous threads here on walnut blasting and several of those include the parts involved in creating your own. Maybe that will help you decide.

 

Sorry, I should have been more clear. I used crushed walnut shells. And I have the siphon-feed setup as described. It just doesn't suck, in my case

 

Yep, that will work better...but your air supply needs are much greater. Plus you'll still need a nozzle to get the walnut shells into the intake.

I used the small blaster too last year and I agree it's not perfect but I was able to get the job done. I believe that there's a thread here somewhere that has all the instructions. You need to follow them very closely to get the blaster to work.

 

I used the same setup and couldn't get it to spray hard, it took me about 5 hours to blast my valves and I went throught the 25 lb. bag twice

 

To the people who have had issues with the blaster spraying hard, what did you use as your air source? How big was the compressor? What pressures does it deliver?

 

Ingersal Rand 7.5 hp, 240v, 80 gal tank, 175 psi works for me...

But seriously, you really need a big compressor to use blasters, and hvlp paint guns, and sanders.

 

Good to hear. I assume everyone else is using smaller, at home tanks. I'm blasting the valves this weekend at the shop I work at. Its more in line with your Ingersal Rand tank, maybe just a bit larger.

 

I'll give it a try. I have a Campbell-Hausfeld 7.5 hp/60 gal / 140 psi compressor, which runs 13.5 SCFM @ 90 psi. The biggest problem is adapting the wand from the HF blow-gun to the 3/8 pipe thread at the output of the blaster. I think a 5/16" compression fitting might work.

 

i just used the 20lb media blaster from harbor freight and it did not work how i was hoping. The biggest ceramic tip that came with it was not big enough for the walnut shell. however the siphon feed gun that i bought from tractor supply had a 3/8" nozzle and it worked without plugging up. i modified it with a blowgun tube by rounding the fitting on the grinder then adding electrical tape to fill the gap. to get down and around the valves. i noticed if the tube size was too small then it would negate the suction feed. so it was a little give and take until i got it set up correctly. I have a 20 gallon that runs 6.5 scfm @ 90 psi. i would spray for 15-20 seconds and then let the compressor catch up while i let the vacuum catch up on all the shells in the intake.

 

I removed the ceramic piece and installed a brass piece instead. I'm doing the blasting today so I'll let you know how that worked.

 

Thanks, I look forward to hearing your results.

 

Update: This works great! I went to Mcmaster-Car, and ordered the following:
1) #89895K732 Type 304 Smooth-Bore Seamless Stainless Steel Tubing, 5/16" OD, .183" ID, .065" Wall
2) #8239K49 Quick-Assembly Stainless Steel Tube Fitting, Straight Adapter for 5/16" Tube OD x 1/4 NPT Female
3) 50785K28 Medium-Pressure Brass Threaded Pipe Fitting, 3/8 Female x 1/4 Male Pipe Size, Adapter

This was the only tubing they carried that had approximately the same ID as the aluminum tube in the HF blow-gun, and I cut a length off and bent a 90 degree angle in the tube with a brake line tubing bender. I unscrewed the ceramic housing from the HF hose, leaving a 3/8" male thread. I clamped the tube in the 5/16" tube compression adapter, screwed in adapter to get the compression fitting on to the 3/8" male fitting from the hose.

I set the media valve and the throttle valve to about half, and opened the valve at the tip of the hose wide open. Worked really quickly, I'd go about 2 min (which would empty my compressor tank), and stop and take a look with a flashlight and inspection mirror. Took about 3 applications (6 min blasting) to clean all the crap off the valves and the intake. I spent more time checking my work than actually blasting. One key is make sure you use fine ground walnut shells. I was given coarse by accident the first time and didn't notice, and they did nothing but jam the output tubing.

Overall, great tool for blasting the carbon off the intake valves! Thanks for all the tips.

 

Update: I ended up opening the media valve all the way. The blaster periodically clogs at the feed valve, and needs to be shaken to free the clump. The metal tube heats up at the bend when walnut shells are feeding, but cools off when the walnut feed jams and you have just air. By holding the tube you can tell by feel when it's time to reach over and give the blaster a shake.