Hey guys,

So I wrapped everything up in plastic, hooked up my fresh air mask and decided to give it a wearl today. Never did anything like this before so wasn't even sure what to expect.

First off, sandblasting is definitely has its drawbacks:
1) it went rather slowly (then again, not sure what I was thinking would happen here). In 15 minutes it did about 1/4 of the wheel well.

2) my 7hp, 60 gal compressor was keeping up (I think) when I tried 60 psi. When I did 85 psi, it was definitely slowly falling behind. At 85psi, it did blast away faster than at lower pressure.

3) I have 3 nozzle/tip sets. I used the medium ones. Which ones should you use in what circumstances?

4) sand gets everywhere. I am not worried about the garage because everything is enclosed in plastic and that did a fairly good job. But I came home I had sand all over including in my underwhere. That's just not comfy. I am doing something wrong, or is that necessary evil? I wore googles, mask, and hard hat that came with the blaster.

If my girlfriend sees me like that next time, I am afraid she will hose me off in the backyard before letting me back into the house like that.

5) How much sand should I expect to use for the entire underbody and engine compartment? I already have a ton of it on the floor and I just got started. Is it reusable? Or should I buy more? If I can reuse it, should it be sifted through something (don't know what since I would have to buy it)?

 

What are you trying to remove? Is it just paint and rust or is it undercoating? Undercoating can big a big hassle if you do not use the right media. Also, check to make sure you are getting a good siphon on the media......sometimes this can be the culprit of lack luster results. Generally the blasting should go pretty quick. Sounds to me that you might not be getting a good siphon or you are just trying to remove a thick layer of undercoating.

 

I just spent 3 weeks with a scraper and a heat gun removing undercoating. So no, there is definitely no undercoating left.

Right now I am trying to remove the rust and old paint/primer under the car and I started with rear wheel well.

As far as the quality of siphon I am getting, it is really hard for me to determine that since this is the only gun I ever held in my hands. How would you go about checking something like this?

Also should I be using larger or smaller nozzle, or is medium one fine for most cases? I only had 30 minutes to play around with that stuff yesterday. Going back tonight, so we'll see how much I can actually get done.

Still need to do something about personal sand control

 

Over a period starting last summer I sandblasted my entire engine compartment. Here's my suggestions for you.

---Don't use sand. While cheap it doesn't do as good of a job. Check out www.consolidatedstripping.com and order some black magnum. You also might be able to find Black Beauty blasting media somewhere near you. I live in the sticks and couldn't. If your doing a big area order 3 or 4 bags.

---If you using a siphon blaster stop now and get a pressure blaster from harbor frieght. You can get the 40# size for around a hundred and pressure blasters work a lot better and faster than the siphon units. They also use less air. Make sure you get some extra nozzles. As the nozzle wears it flows more and you'll need more air.

---- get a good sifter. I know eastwood sells one. Sift even the brand new media. Get some 5 gallon buckets. Sift the stuff into the buckets then fill your blaster. when you run out sweep it up resift it and start over. I found that after a while the media gets a lot of the crap you blasted off in it and stops working well. At this point just ditch it.

---- Make sure you have a good moisture seperator in your air line. The moisture will clump up the media and make blasting a PITA. When the compressor is running constantly to keep up the air gets hot and as it cools in the lines you get a lot of water.

---- some coveralls are great to wera while blasting. Since they are one peice there is less places for the grit to get in your undies.

 

thanks tojan,

actually now that you said it, I am using black beauty (if it is not sand, what is that stuff then?) that I bought in 100# bag from my local paint shop that also sold me that siphon blaster. I'll check with them tomorrow, maybe they actually sell the sifters as well.

I actually went the paint shop on purpose knowing that HF isn't exactly known for quality. I have a lot of things from HF and some do work, but I was actually hoping to find a more decent unit and that's why I went else where.

About the water in the lines, that could very well be my problem. When I was using the air drill and die grinder to clear out some other stuff a couple of times it really started spraying me with water. I guess it is time to put that desiccant filter to good use.

 

your going to want to use something other than a dessicant filter. Those are good for spraying paint and use as a second filter but will quickly be ruined by the amount of moisture you'll be putting out. Get something like this
http://www.lowes.com/lowes/lkn?actio...108&lpage=none
I would get a bigger one if I had to buy a new one. While spraying primer for my engine compartment I filled the little jar full of water! It was pretty humid though. If you use one of those you probably don't need the extra step of a dessicant dryer for blasting.
The HF pressure blaster is an ok deal. By the time I was done the vavles were worn out from media running through it but it worked fine. Pressure blasters require a little bit of tuning when you start to get the right mix of air and media. I agree that some stuff from HF is junk. I would reguard their blasters as a decent disposable tool. Unless you spend the extra $10 to get the one year warrenty like I did. Now that I'm done and the valves are worn out I'm just going to get a new one and leave it in the box until I need it again.

 

k, following everyone's (including some random customer guy at my local paint store) suggestions, I went and bought 40# pressure sander from HF.

Comments:
1) I was very suprised to find that assembly directions were actually clear and made sense.

2) Did anyone else have every other fitting leak air. I used more teflot tape, less teflon tape. Tighten normal, then more, and then some more. Eventually went to Home Depot and replaced all fittings with regular ones, except for the one that had a flared end. That flare isn't even a standard size, so I was stuck with that one. Then I decided to use teflon goo instead of tape, and I think that was a mistake (unless I should have let it dry for 24 hours before using).

After fudging with it and 3 trips to the hardware store, I got everything assembled and put about 20lbs of sand into it.

More comments:
3) it does work way faster than syphon feed. I can probably reduce pressure now (it was at around 90psi) just because everything is blasted away so fast. And then compressor wouldn't have problems keeping up.

4) The valve at the gun itself is always leaking air, even when it is completely off. Is that normal?

5) I can't seem to get a balance between how much sand I need. At first I left all valves open and as soon as I started blasting, nozzle got clogged up. Then I tried not opening the sand feeding valve all the way so that less sand is fed into the gun. When I did that, sometimes sand would stop flowing through the gun at all and I would have to tap on the tank to get it going again. Then again, I tried the second nozzle by size thinking it'll reduce air consumption. Probably if I increase the nozzle size to the maximum it won't clog up as much.

Any responses to any or all of these?

Overall the impression I have is that it is definitely a better tool in terms of speed than my other blaster, but it does feel like it'll become garbage near the end of this job (hopefully after I am done with the underbody).

 

The valve for the blasting nozzle does wear out a bit quickly and will leak a bit. I didn't have any problems with the other fitting leaking. If I remember correctly the best way to get it balenced probperly is to open the bottom valve and close the top one. Then slowly open the upper valve to get the right mix. I'm not possitive on this. You might want to call consolidatedstripping.com and ask one of the guys there. He helped explain to me how to set up mine.

 

yeah and while manual was good about assembly instructions (full credit to whoever wrote that section), the entire thing didn't even mention what those valves were for or how to use them.

I was guessing there is some kind of balance that needs to be found, but are you sure it is not the other way around? If I open the bottom fully, it seams that it just dumps a ton of sand into the airline. I was trying the same thing, but in reverse. I think I almost got it because it did spray continuously for longer than other tries, but then I ran out of sand.

 

I have one of those HF pressure blasters as well. I have used it quite a bit, and have found that it is best to open the upper valve to pressurize the tank while leaving the lower valve closed. Then after the air is flowing, open the lower valve until I get the amount of sand flowing that I want, then blast away. I occassionally have an issue with the sand clogging the lower valve, but usually just rock the tank to get it flowing again. I have the most issues with clogging when trying to use the smaller nozzles.