a little off subject,... sandblasting

[WillBilly53]

i've got a problem. i've been trying to sand blast my intake and timing chain cover, but i can't get it to work quite right. i've got one of those "blast out of a bucket" things. it sometimes works, and it worked fairly well the first time i used it. the sand is not wet not even damp. it's completely dry and i can feel the compressor pulling it up, but hardly anything comes out. i've check for leaks - none. then all of a sudden yesterday i had a huge "blast" for about 2 seconds and it instantly turned the rust into beautiful cast iron gray. i was messing with the end of the sandblaster that sits in the bucket (the long metal rod). my questions is:<BR>does the bucket need to be physically lower or higher than the gun or the compressor itself?<BR>is there something i'm missing. i've checked the nozzle several times and it's not getting clogged. i'm using a porter cable 6 hp 20 gallon tank and it Provides 8.6 SCFM at 40 PSI and 6.8 SCFM at 90 PSI i'm running at around 90 psi. can anyone help me? please! i've looked all over the internet for help and i can't find anything.<P><BR>thanks in advance,<P>will e.

[Guest Albert]

try taking the gun apart and looking for manafacturing burs inside where the rubber tube fits on to the gun, also the position of the jet also makes a difference, mine now has too much suction, and had to pinch off the pickup tube somewhat to restrice the flow or the pickup pipe will plug. Now have a pressure fed tank which works better.

[WillBilly53]

thanks arthur! <P>[ 08-03-2002: Message edited by: willbilly53 ]<p>[ 08-03-2002: Message edited by: willbilly53 ]

[Guest]

make sure that your blasting medium and tip match.

[old-tank]

In order for a siphon unit to work there needs to be a vent in the pickup pipe above the sand or a parallel vent pipe down in the sand. Be sure the hose that connects to the pickup pipe is not covering the vent hole and that you don't have the ends switched. (you can cover the vent hole sometimes if used as a liquid blaster). Disconnect the hose at the gun and verify that vacuum is created when you trigger the gun on.<BR>Hope this helps<BR>Willie

[NTX5467]

I know that sand is a common blast media, but you might have better luck with glass beads or plastic. I suspect the glass beads or plastic might not be quite so critical to moisture as the sand can be and still work well. As always, make sure the gun head matches the type and size of the blast media.<P>What about using some of the liquid dip rust remover solutions instead of sand (provided they are compatible with the metals you are cleaning)?<P>Just some thoughts . . .<BR>NTX5467

[capgage]

tony, ntx:<P>How would you match the gun head (are you talking about the ceramic nozzle?) to the size and type of media?<P>Will,<P>I have found that if I am running low on sand, it doesn't flow as well. Maybe you should try adding some more to the bucket, so there is more weight above and therefore more pressure at the bottom of the bucket where your pickup tube is?<P>Also - you are wearing a good resipirator, right? Even when I wear one that is as airtight as I can get it (this is not an air fed one, but is approved for "nusciance dust"), I find that my nose and throat are irritated the next day. That silica is really bad for you long term.<P>Mark

[brad54]

An old trick is to (with heavy leather gloves on!!!!) put your palm over the nozzle and depress the trigger, blowing the air back down through the pick-up tube and blowing out the sand. If you have something plugging it up, this will blow it out and open up the flow. That's really handy in a blast cabinet, where rust and debris can get recycled into your sand.<BR>I thought you dipped that thing in vinegar already, didn't you?<BR>-Brad

[NTX5467]

Last time I knew about sandblasting equipment, which has been a while, the sand came in "fine", "medium", and "coarse" grades just as regular sand paper did then. Similarly, you used the sand in a manner such that you used the coarse for the quick cut of heavy accumulations, then switched to the finer grades for finish work. Your instructions with the unit might have covered that strategy and should also indicate what media the existing spray tip/nozzle will work best with.<P>With respect to filter/respirators, the type the body shop painters used to be advised to use had two round filters in the front and acitivated charcoal in the filter mix also (looking somewhat like a WW2 "gas mask"). If the one you have is rated for "nuisance dust" you might see if there are any filters for it that will filter down to a smaller particulate size. Some of the automotive paint suppliers in your area might be able to help in that situation.<P>Hope that might help . . .<BR>NTX5467

[Guest]

thanks everybody!<BR>okay, i have the gun with a ceramic tip. and it said it was for sand. <BR>i couldn't find any manufacturer burrs in the gun, but i will check the venting, and refill the bucket (it was getting a low)<BR>another thing, i was told i could use just play sand like you find at lowe's or home depot. was i told wrong? could this be the problem also? and where can i get glass bead media?<BR>and yeah i did already dip this thing in vinegar, but i didn't know how to prepare it after i pulled it so it wouldn't rust again, within minutes it was turning orange! it looks worse than before.<P>so i'm back to square one. <BR>ntx - when you say possibly using a liquid rust remove do you mean like naval jelly? or is there another product out there that i'm not aware of? could i use vinegar? - granted i treated it the correct way after i'm done? by the way, how do i treat it? i know i can use wd-40 on the inside, what about the outside? i plan on painting it.<P><BR>thanks!<P>-will

[palbuick]

Try Siica sand, it is much finer than regular sand, and is fairly reasonible. I bought it at my local lumber yard, in 100 lb<BR>bags around $5.00 bag. Some hardware stores will also carry it. Play sand is too course this my be why your nosel is clogging. If you are using a gravity bucket they are very slow and use a lot of air pressure. For outside work use a pressure feed type blaster. They work a lot faster.<P>Jim Schilf / palbuick@aol.com

[capgage]

Will,<P>As you are finding out probably, sand suppliers have been gotten ahold of by the litigators and all will tell you not to use their sand for blasting - will even tell you it is a carcinogen, causes silicosis, etc. Which I do not doubt it would if you sandblasted without a respirator every day. Most of us do not do that.<P>Consequently, sand is not available in different grades as far as I have seen other than play sand, all purpose sand, and garden sand (which seems chronically moist). I don't know where to go to buy it in grades varied for blasting purposes anymore.<P>So I am planning on using some play sand also, since at least it is much more uniform (though admittedly course) than the all purpose sand which seems to have all grades of sand combined in it.<P>About eight years ago I was able to buy "blasting sand" at Builder's square. The play sand I just got at Home Depot to me looks to be the exact same grade as that old blasting sand that I am now running low on.<P>Jim, all sand contains silica, right? I just went by 84 lumber and all they had was the all purpose sand used typically for concrete. I wish I could find the "silica sand" that you are using for outside blasting, sounds like that's the stuff you want.<P>In my cabinet I use aluminum oxide. You can buy aluminum oxide and glass bead at Harbor Freight. They also sell an apparently decent pressure unit that I want to get for outside blasting (I'm now using a craftsman siphon unit). Maybe by the time I get the pressure unit I will also find the better sand to use.<P>Oh yeah, I think I'll need a bigger compressor at that point to. I'm now using a 5 hp 20 gallon Campbell Hausfield, which I am thinking cannot last much longer with all this blasting. Don't the pressure units require more CFM? (maybe at lower pressure though...)<P>Mark

[Guest]

so is there a pressure feed type blaster that is under $300? i just spent $400 on the compressor and stupid syphon! ARRRGGGH! <BR>i'm really frustrated right now.<P>on a lighter note:<BR>which works better to remove rust? glass, aluminum oxide, or sand?<P>thanks,<BR>will

[capgage]

Will,<P>Don't be upset - that pressure blaster needs a bigger compressor than what you just bought to run it. You did the right thing.<P>In a cabinet, aluminum oxide is the best for removing the rust. Next best in the cabinet is glass bead, it's less harsh on the surface.<P>For outside blasting, it is too expensive to use either of these if you ask me. Your best bet is blasting sand - since my last post I have found some locally. I looked up masonry supply on yahoo yellow pages. I will not be using the play sand after all. I just had to dig a little to find what I needed.<P>Use a painting-type respirator, as mentioned above...<P>Shoot me an email - mark_schmerbeck@amat.com<P>Mark<p>[ 08-05-2002: Message edited by: Mark Schmerbeck ]

[WillBilly53]

thanks mark,<P>i've cooled down a bit. (even though it's hotter than 40 down here in charleston,sc)<P>i've got some things to check out when i get home, so i feel better about that. if i built a cabinet, i could conceivably re-use the media, right? like if i made the cabinet out of wood and lined it with some kind of rubber? anyways, that's another subject...<P>i'll stick with the sand. i'll try looking up that blasting sand as well. and thanks for the reminder on using a respirator!<P>thanks!

[NTX5467]

Seems like POR-15 has a good rust remover liquid/gel that seems to work reasonably well from the demos I've seen at the swap meets. Seems like there's another brand too. They might all be the same stuff, but it might take a chemist to determine that. They all typically neutralize with water.<P>The "carcinogenic" issues are related to the particulate size of the dust. I suspect the EPA stance on these things are somewhat overblown (all things considered), but that's probably where all of that dialogue originated. A blast cabinet really is the best way to do small work as it keeps things a lot cleaner and the media is easily recycled.<P>When we were doing the sandblasting activities a while back, we went to a commercial sandblaster locally and bought the sand. It might have been more expensive, but it was local and it was in grades.<P>Be sure to follow the sandblasting with a good metal prep that will get into all of the little craters in the "cleaned" part. If this is not done, the paint/primer will skin over and not penetrate well--result is poor adhesion and other issues. We sandblasted a vehicle, primed it, and within two weeks of dry summer weather, rust was popping through the primer. We took the "advice" of people who should have known and primed the bare metal without metal prepping it.<P>Since those days, there are all kinds of new blast media. Glass beads, aluminum oxide, soda, and even plastic. Just as with wetsanding a paint job, use the blast media to just take off what you're wanting removed and maybe even stop early so you don't remove too much of the base metal with your activities.<P>NTX5467

[brad54]

Try your local automotive paint supply store. Mine sells sand and glass beads. They might sell other media, but I never checked.<P>If you strip the intake in vinegar again, and IMMEDIATELY wash it, then spray it with WD-40, that should hold until you're ready to paint. I'd use an old towel to dry it, rather than compressed air. Then get a can of alcohol or something to cut through the WD-40, wipe it down and paint it. <BR>I'm going to do a 322 intake--after reading your post about it rusting, I'm going to have a bucket of water and go straight from the vinegar to the water and dunk it, then dry it and WD-40 it.<BR>-Brad

[Guest]

harbor freight has a little pressure tank blaster for around 100.00 that works fine. good luck

[NTX5467]

I've never heard of using vinegar for those things (any particular type?) but that doesn't mean it doesn't work.<P>From my experience, WD-40 is only good for short term protection (although other people might state otherwise--just my experiences). As for cleaning whatever petroleum based coating you put on the manifold between cleaning and paint operations, I suspect that brakeclean spray might be the best option as it removes all oil from the surface. Before that, I had good luck using Berryman's B-12 carb spray cleaner. I suspect anything that will cut the oil will work, but the brakeclean should dry with no residue. Putting it in a plastic bag to keep the moistsure rising and falling more away from it.<P>Instead of the towel, I might recommend a hand held hair drier to speed things along a little. Probably using an intermediate setting with some of the blue "reuseable shop towel" paper towels made by Scott (I believe).<P>As for engine paint, if you don't buy the desired color from a vendor, you can get some hand matched mixed at a local paint supplier-if they can't find the correct formula. I got some acrylic enamel mixed for some valve covers many years ago and it worked great, using one of those PreVal spray units that many of the paint supply places sell (a glass container topped by a screw on pressure "can" that makes the whole setup a customized spray can that is reusable).<P>A Pontiac guy mentioned years ago that painting the heat crossover area of the intake with the Eastwood high heat paint before putting the final engine color on the manifold seemed to lessen the heat bake of that area with use.<P>For the black parts of the engine, I have found that GM Glossy Black Engine Enamel is a dead-on match. Even though the word "glossy" is in the title, it is a satiny, semi-gloss paint that matches air cleaners, brackets, and anything else on the motor that was black. Even works for Chryslers too.<P>Many of the "correct" paints sold by the restoration people are not quite as "correct" as they are said to be and in some cases are too glossy or of an incorrect shade for the particular application. End result is that shiney black paint exists in places that GM never put shiney black paint at the factory.<P>Everyone has their own particular way of doing things or things that work for them, these are mine and others can work well too.<P>NTX5467

[DugsSin]

Silica sand can also be found under the label of "pool filter sand" There are several grain sizes available.<BR> I spent a bunch of money getting a nice blast cabinet from TP Tools (960 Pro) Picked it up myself at carlisle and they make you a better deal than the catalog. Worth every penny <A HREF="http://www.tptools.com" TARGET=_blank>www.tptools.com</A> <BR> Doug Updike BCA# 33850

[Guest]

Thought I would add some more fuel here!! <BR> Having used both types of blasters I have to recommend the pressure over the suction. The suction takes a lot of air to keep it working and you will never get the volume of sand like you will with a pressure feed.<BR> I got mine at harbor freight for 100 bucks.<BR>Running a 6 HP Cambell Housfeild single stage compressor.<BR> I get about 4 minutes of blasting time until im down to a point where the air flow is too low to be efficiant.<BR> So.....I sit there waiting for it to pump up and think about what im doing on the car! (quality time)<BR> Put out a tarp if your doing large parts and use a screen every time you dump your sand into the tank. Its very frustrating to keep getting plugs in the hose and tip!<BR> I made a portable sandblast booth out of some 1 1/2 inch pvc and some elbows. Made it with 3 sides and then I hang a plastic tarp all around it with the C clips.<BR> Works great and you can take it all aprart when your done for storage.<BR> You can see I have blasted my entire car with this blaster.......<BR> <A HREF="http://members.cox.net/oldies1955/web/dodge_page.htm" TARGET=_blank>http://members.cox.net/oldies1955/web/dodge_page.htm</A> <P> Im using silica sand with a paint resperator.<BR> Be ready for getting sand in every orfice on your body though!!! LOL Its messy, especially when your under the car.<BR> Hope this helps<BR>Tom H

[WillBilly53]

tom thanks a billion!<P>i'll pay a "visit" to harbor freight when i get my next paycheck!<P><BR>thanks everybody!<P>-will e.

[capgage]

bwahaha- (evil laugh)<P>The 40# pressure units are on sale for $80 for the next week or so at Harbor Freight (just bought one, haven't used it yet). <P>I take back my statement from earlier about your compressor not being able to run the pressure blaster - apparently it takes MORE cfms to run the suction unit than the pressure unit.<P>My compressor is a measly Campbell Hausfield 5.5HP, 20 gallon tank (actually, I've never had much of a problem running my blast cabinet with it). We'll see if I can't burn it up and upgrade to a 220V 60 gallon compressor (more evil laughter).

[capgage]

Tom H,<P>Can you tell us more about your portable blasting booth? I was thinking of doing something similar with one of those canopy frames, like the ones people use on the beach or for camping.

[Guest]

I have heard rumors over the years that sand blasting aluminum parts imbeds tiny bits of silica in them. I've been told that these bits can flake off over time and can get into your engine (even when the part has been washed clean). Any truth to this tale?<P>Greg

[Guest]

Take your sandblasting to your local cemetery monument company/dealer. They most likely can advise you about sandblasting and if you want, may be able to do the work for you. I own some old cars and a monument shop. A nice combination. We do sandblastng for outside folks and are happy to do it. we charge $45 per hour and break even on these jobs. Good luck.