Ok here's the situation, I'm working on getting my car ready for paint. so with money being tight as usual, I thought I might save some by stripping it myself. So I called up Eastwood and ordered a 100lbs sand blaster with 6 50lbs bags of walnut shells. anyway today I tried it out on my hood and ended up using 100lbs of my walnut shells just for one side! At this rate i'm going to need a TON of this stuff just to finish my car! So my question is, is this normal or am I doing something wrong? Any help you guys and gals could give me would greatly be appreciated. Thanks, Ken
I never used nuts to blast with...but just a guess is that you have the mixing valve set way wrong. Like with sand, it is set fairly close if you can barely see the sand coming out of the nozzle when viewed from the side. Yes, it will clean quicker if the mix is set rich, but uses way too much media.
walnut shells are too soft, they wont work for hard blasting on steel. And YOU WILL use a lot more than you think regardless of media! Plus, you need HUGE CFM to make it really work. Eastwood makes it sound like anyone with a Cox .049 attached to a tank can blast.
Does "one side" mean the whole outside,or 1/2 of one side?I've never used walnut shells,but I think I could probably do a whole hood for a 50 chevy or 59 Ford with 100lbs of sand.I go to Carter lumber and buy quikrete "medium sand" .Under $8 for 100lbs.
do the shells look really busted up or do they look almost like they just came out of the bag, you may be able to pick it back up and reuse it, i would screen it with a screen just a little smaller then the nozel, most media can be used over and over till its nothing but powder. also when i'm blasting i like to turn the air on forst and then the media, then i turn the media off forst and then the air, that way i dont have the hose fill up with media and all come pouring out when i start back up again, i use my toe to reach in under my pot to turn the media ball valve on and off.
what pressure are you running, what size of blaster are you using? walnuts are fine, less sheet metal distortion. to increase the effectivness you need to run higher air pressure and have the cfm to back it up. you cant run a blaster the size of a garden hose from a tire/ball inflator compressor. sounds like the blasting media is mostly bouncing off the surface instead of actually blasting
Well, it was probably a total of a couple of hours worth of work but most of that time was spent waiting for my compressor to catch up (60 gal). It was just the under side that i got done. when I started on the top it didn't seem to want to get all the paint off and by that time I was getting frustrated so I called it a night and cleaned up. I did sweep up what I could and am going to try to reuse it (after I strain it of course). As for the size of the tip, I tried a 3mm first but it kept clogging so I jumped up to the 5mm and didn't have any trouble after that. I'll try to fine tune my adjustment nozzel but I'm thinking my compreesor just dosen't have enough cfm to do the job. Il'd switch to sand but i've heard all sorts of horror stories about worping and such. Thanks for the help so far! Ken
I'm not a big fan of paying close to 40 bucks a bag for any kind of blasting media unless it is kept in a blast cabinet with a reclaimer. I am a fan of the black coal slag called "black blast" sold at Menards for under 10 bucks a bag. The edges are very sharp and it doeen't throw out a lot of dust. You can recycle this a few times with a big funnel and a spaghetti strainer before it breaks down to dust. You do need to build yourself a portable booth to blast in to be able to sweep the stuff up to reuse. You can do this with 16 - 20 8 foot 2x4s and some heavy plastic. Always be careful when blasting any flat surfaces and keep your tip moving to avoid heating up and warping the metal. And above all use proper breathing and eye protection. Right now is perfect outdoor blasting weather in the Midwest. Good Luck Bob
I have been using sand from Home depot for years, then a couple months ago I broke down and bought glass beads from harbor freight......never lookin back. Blasted all the front suspension parts a arms springs strut rods etc in an afternoon. WAY faster than sand and super fine to get in the nooks. watch out though their slick under the feet! Oh and hardly any dust as well. I dont know if the glass poses a problem for paint as I had small enough parts to clean very thoroughly
If any hambers that blast were there in person, it would be easy to see what is going wrong. But the info about waiting a lot of the time for the compressor to catch up, and going from a 3mm to 5mm..... I would think from this info, that you should switch to screened sand to get back to the 3mm nozzle. There is a huge CFM change in those two sizes. There were charts to show CFM requirements to maintain a certain pressure with various nozzles. Rust needs either more pressure or lots more time per square inch to clean, rather than just old paint with no rust. So, if you have no surface rust, you can get by with lower pressure, which is a good thing so you don't warp flimsy surfaces. Higher pressures and chasing deep surface rust can cause warping from concentrating on one spot too much. I try to use a nozzle size that lets me maintain a certain pressure (around 80 or so)with my two compressors running full time. I use fans on the compressors motors in summer. I blast for 30 to 45 minutes at a time.
I run a regulator between the compressor and the blast tank. And 1/2 inch ID hose from the comp to the reg to the blast tank . 60PSI coming out of the regulator into the pressure tank. Minimun sand delivery, I have a 5 hp comp and it will keep up with continuous blasting. I use play sand and don't know the nozzle size.
5mm = 3/16" that's a huge nozzle for a little (cfm) compressor. I have a good sized two stage compressor, and it can keep up with a fresh 1/8" nozzle, but if it wears noticeably then the pressure drops. Pick a nozzle that lets the compressor almost catch up, and use fine sand, try to get the mixture lean (so you can barely see the sand come out), and see how it works
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