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sand blasting questions


Los_Control

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Seems my old pick em up has some surface rust, been fighting it with acids. They work but not ideal.

Anyways, local thrift store had a sand blaster for sale, I bought it. Now wondering what type of blast media to buy.

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Wondering if others have a preference from their experience . Limited to tractor supply, but I see they offer fine & medium for less then $10. Then they have some different buckets called garnet or glass, they are $30 .... just wonder what the smart people think ... probably just pick up a couple $10 bags to start with, wondering fine or medium?

My air compressor is too small to begin with, hoping can get a short 2 or 3 min run, then wait for it to build back up. Wonder if fine or medium sand will have a affect with lower air pressure?

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dress out right, proper respirator and protective clothing.....use sand...best over all media for this use....the other media is more expensive and worth it in a recirculation style cabinet blaster.  Most large compressor repair companies also sell sand blasting sand.....it is the better price, it is correct graded grit.  You can use a tarp back drop and collect and reutilize your sand a few times....basically when it drifts away in the air...it is too small to reuse.  Again, dress out....with this style blaster you will want to modify it for good clog free operation and do KEEP your air supply clean and dry.  I recommend that you always cut your sand flow off at the bottom of the tank with a ball valve over use of the dead man….the dead man will allow the hose to fill with sand and spurt and clog and waste sand like nobody's business....

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Note to self: DO NOT PLAY WITH THE SANDBLASTER IN THE GARAGE!

 

Actually works pretty well, I see what you mean Adam. When you pull the trigger a glob of sand falls on the floor, then it starts to spray.

Boy just a couple quick burst, sand all over the place to be cleaned up. I really think this is the tool that will help me speed things up on my project.

Been wet sanding with 80 grit and making progress, but some areas is like hitting a dead end and going nowhere.

60 seconds with this blaster, I cleaned a lot of rust effortlessly.

I see myself tarping off my carport and using proper respirator, ventilation in near future.

 

Off to tractor supply to buy some sand, going to go with course and also buy a pack of nozzles, think a smaller diameter nozzle will require less air.

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I cannot OVER RECOMMEND the control of the sand output by use of the ball valve...your air jet will control the sand more than the nozzle....you will learn to control the sand with the ball valve...you will find moderate air pressure with better sand control to be a very good balance and allow you to sandblast an entire car in just a few  hours....I did my 54 it two evenings after work...that was at 4 hours each evening including taping and putting away stuff my toys......

 

the pressure pot is a great investment when you set it up right and get used to it....DRY AIR....DRY SAND.....moderate flow and pressures all work together....absolutely no warpage...I also recommend a few old blankets....these you place around areas you wish no sand to drift....soak these with water......they work miracles as filters....

Edited by Plymouthy Adams
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8 minutes ago, Plymouthy Adams said:

I also recommend a few old blankets

I just happen to have two puppies .... hoping they are done teething, at 1.5 years old .... they created lots of old blankets  ;) And I saved them.

Now if I can get them to stop digging holes  ?

 

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ASPCA is on their way to your house now!!   ?

 

DJ

Edited by DJ194950
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The grit of sandblasting media is for both cutting and surface texture after you finish.  Virtually any hard media grit will leave a wonderful surface for paint to stick to.  The thicker the material you want to remove, the bigger the sandblast media you want, then judge the bare surface for if it is what you're looking for.  I have always used a medium grit, and get great results.  Fine would be more for glass etching and the more delicate parts, and can even be used to get some polishing started.  I've never used coarse, so would have to defer to someone else on that.  What the media is made from can determine the finish, and what to blast, too - but, I think TSC doesn't have a vast array of options, anyway.  The nozzle size is for the grit of the media you're using, coarser grit, bigger nozzle.  Most grits/materials will have recommended PSI to work with for best cutting, and longer lasting media.  Exercise caution when blasting not to spend too long in one area, just like welding, blasting will heat metal and warp it if working in one spot too long.

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I appreciate the tips from all, not sure my dogs do  :D

Dan Hiebert those are good tips.

I have been watching a few youtube vids and really not much out there worth watching.

I am really just going to have to feet wet and dive in. I did pick up 100 pounds of medium sand yesterday.

Kinda shopping around for a better air compressor, I have a porter cable pancake compressor that is great for nail guns, not made for steady air flow. Yet it surprised me how well it kept up.

The Sand blaster removed the heavy rust on a rear fender so quickly, was no reason to slow down the movement.

You can see from photo where I started from, now I have the front sheet metal pulled and worked it all over by hand, stored inside.

Just waiting for better weather where I can blast and then paint. Texas weather, was 80 degrees last week, 30 degrees this week and 70 next week  ?

 

 

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Epoxy primer is high in resins...use it to seal the metal asap.

when you're ready to do body work, you can grind back how ever you like and epoxy again.

Shaping can be done with urethane primer, its better for sanding etc.....

A thinner mix of epoxy for a sealer.

 

Leaving it bare, you should cover parts up with a thick blanket until you get to primer...just not to terribly long.

 

If you are fighting rust with acid, that's only a small part of the fight. Rust will come right back unless the metal is closed off from oxygen.  

 

Etching primers are acid based and good for areas that are hard to sand (ie hard to reach)

On extremely rusty panel, after sanding, some guys will use etching primers first.

Because of better (improved) products, epoxy primers are typically used without using etching primers.

If you do use an etching primer, you have to check that an epoxy can go over an acid based etching primer.

 

48D

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I had an acid tank set up behind the shop, and when I stopped working on the car (sometime in 82 or 83) I had some duplicate parts from the parts car that I had never painted after pulling them out of the acid bath (phosphoric), and they were left that way all these years.  Still not rusted.  Phosphoric acid leaves a film on the steel that rust does not penetrate.  (This was straight acid, or maybe as much as 30% water at the most, not phosphoric 'metal etch'.)

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Acid works pretty well, is how I got things as clean as they are now. But it is a pain, maybe if I had a tank that could dip in I would probably go molasses. I have had great success with it and easy cleanup .... dump it in the back 40 and acts like fertilizer to the grass.

I do not have a tank, and I have dogs .... I do not think would work well for me. (at this time) Later I want to build a small shop and maybe then can be arranged.

Regardless, like any job there are many steps and a sand blaster is going to be useful.

I used acid by brushing it on, phosphoric acid you can see on the tailgate.

It turns the rust black, the white powder looking residue means I did not use enough. But the rust is converted and held at bay until I can get to finish it.

I actually needed to use murratic acid to remove the rust (nasty toxic stoofs) to bare metal, then I wet sanded it and cleaned diluted it and then used phosphoric acid on it to keep it from rusting while I wait for better weather for paint. Because I am spraying/brushing wet sanding, some areas are difficult to get to and sand blasting will be the right tool for those areas.

 

With all that said, this sand blaster is turning out to be aggravating.

I did a trial run with it in the garage the other day and it worked well and was using the media that was left in it. I figure to use it up.

Then I set it up outside, got all my protective gear on, respirator, safety glasses and gloves, plastic on the ground. I blast for about 20 seconds and the hose clogs up.

I put in fresh media and same issue. I remove the tip and turn the air on and it spits and sputters and cleans itself out, put the tip back on and it clogs up again.

Guess I will drain all the sand out of it and start fresh and see how it goes.

Guessing it is moisture causing it, even though it has a air filter to catch the moisture, no way to tell how old the original sand is, I added fresh on top of the old but that does nothing.

Next guess would be not enough air pressure, I turned the compressor down to 90 psi to try and make it last longer .... hrm, maybe I go back and crank it up first before trying anything?

Says minimum of 60 psi to run it.

 

DOH!, more air did the trick .... face palm

 

Edited by Los_Control
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10 minutes ago, Los_Control said:

Acid works pretty well, is how I got things as clean as they are now. But it is a pain, maybe if I had a tank that could dip in I would probably go molasses. I have had great success with it and easy cleanup .... dump it in the back 40 and acts like fertilizer to the grass.

I do not have a tank, and I have dogs .... I do not think would work well for me. (at this time) Later I want to build a small shop and maybe then can be arranged.

Regardless, like any job there are many steps and a sand blaster is going to be useful.

I used acid by brushing it on, phosphoric acid you can see on the tailgate.

It turns the rust black, the white powder looking residue means I did not use enough. But the rust is converted and held at bay until I can get to finish it.

I actually needed to use murratic acid to remove the rust (nasty toxic stoofs) to bare metal, then I wet sanded it and cleaned diluted it and then used phosphoric acid on it to keep it from rusting while I wait for better weather for paint. Because I am spraying/brushing wet sanding, some areas are difficult to get to and sand blasting will be the right tool for those areas.

 

With all that said, this sand blaster is turning out to be aggravating.

I did a trial run with it in the garage the other day and it worked well and was using the media that was left in it. I figure to use it up.

Then I set it up outside, got all my protective gear on, respirator, safety glasses and gloves, plastic on the ground. I blast for about 20 seconds and the hose clogs up.

I put in fresh media and same issue. I remove the tip and turn the air on and it spits and sputters and cleans itself out, put the tip back on and it clogs up again.

Guess I will drain all the sand out of it and start fresh and see how it goes.

Guessing it is moisture causing it, even though it has a air filter to catch the moisture, no way to tell how old the original sand is, I added fresh on top of the old but that does nothing.

Next guess would be not enough air pressure, I turned the compressor down to 90 psi to try and make it last longer .... hrm, maybe I go back and crank it up first before trying anything?

Says minimum of 60 psi to run it.

 

on the clogging...you using the nozzle control for sand flow or have you switched to sand flow control by ball valve at tank exit?   control the sand here....NEVER spit and sputter UNLESS you have a very wet air supply....wet sand packs, it does not flow...be sure to use a water separator on the input....you do not need near the air pressure you think you need when you have control of the media.

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you use this to shut off the sand flow and it rarely ever will need to be fully open.....you just do not have the CFM for that...….use this INSTEAD of the dead man/trigger nozzle...a tad inconvenient in one manner but saves you on aggravation and stopping to clear clogs and thus your production goes up instead of your blood pressure.

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ok gotcha,  Now am wondering if ways to modify the dead man, perhaps install a shut off valve before it, instead of getting down on my knees to turn it off under the tank.

Seems like it may have the same affect as the valve on the tank? Just on the other end of the hose?

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you control the sand anywhere in the hose at before or with the dead man/trigger controlled nozzle.....it will pack sand and clause the clog....prevent this by shutting off flow to the to hose at the bottom of the tank...yes is a inconvenient but so is clearing clogged lines....and keep in mind, all the while it is sputtering sand to clear, it is also pushing sand in behind that clog to make this a long drawn out process that results in an empty tank before any real work is accomplished....

 

 

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18 hours ago, Plymouthy Adams said:

you control the sand anywhere in the hose at before or with the dead man/trigger controlled nozzle.....it will pack sand and clause the clog....prevent this by shutting off flow to the to hose at the bottom of the tank...yes is a inconvenient but so is clearing clogged lines....and keep in mind, all the while it is sputtering sand to clear, it is also pushing sand in behind that clog to make this a long drawn out process that results in an empty tank before any real work is accomplished....

 

 

 

I plan on making a lever linkage to my bottom ball valve that I can easily reach on top or a foot control for mine...because yes, the bending over gets old quick!

 

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2 minutes ago, ggdad1951 said:

I plan on making a lever linkage to my bottom ball valve that I can easily reach on top or a foot control for mine...because yes, the bending over gets old quick!

That sounds like a great idea, I might look into that.

As a old construction worker, I am disabled now because of my back, bending over often is not ideal for me. But I slowly get er did!

 

And with that, am off to the physical therapist for another spine adjustment ... hope to be able to get something done today.

While I am in town I will pick up a new fuel pump from napa, ordered it a few days ago, wonder what quality it will be.

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6 minutes ago, Los_Control said:

That sounds like a great idea, I might look into that.

As a old construction worker, I am disabled now because of my back, bending over often is not ideal for me. But I slowly get er did!

 

And with that, am off to the physical therapist for another spine adjustment ... hope to be able to get something done today.

While I am in town I will pick up a new fuel pump from napa, ordered it a few days ago, wonder what quality it will be.

 

Doctor Detroit did spine adjustments...…..:eek:


 

15 minutes ago, ggdad1951 said:

 

I plan on making a lever linkage to my bottom ball valve that I can easily reach on top or a foot control for mine...because yes, the bending over gets old quick!

 

 

Yes an extended lever would make operation of the valve much simpler....I usually have mine a bit elevated on a platform as it does help with bending over on all processes while blasting.  We all got our certain comfort zone and ergonomics is more than a catch word.  I have two 4 x 8 metal framed tables with plywood tops that I placed larger wheels on for rolling about the yard...these are my work tables for a lot of things I do about the house.  They are being used now for the prepping and upcoming paint on some vintage cast iron patio furniture.  These tables are in constant use.  

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  • 2 months later...
On 3/7/2019 at 1:11 PM, Plymouthy Adams said:

you control the sand anywhere in the hose at before or with the dead man/trigger controlled nozzle.....it will pack sand and clause the clog....prevent this by shutting off flow to the to hose at the bottom of the tank.

I think it finally sunk in, I do have to admit to having a hard head. Been awhile since I started this thread.

Since then I had to do a bunch of work on my house, that kept me from working on projects like my truck  :(

 

I did pick up a better compressor for the shop .... and a radio!

This compressor is still a bit weak in the knee's, twin cylinder, 30 gallon, 5.7 cfm @ 90psi.

I have 1/2 a chance to do something with it compared to my old little compressor to run nail guns.

 

Exact same problem, the hose fills up so quick that it clogs the air .... you control the flow of sand from the bottom of the tank, you do not allow more sand in the hose then you can remove from the hose .... guy can actually get something done .... A wise man once told me this  ;D

 

Sometimes I need to be hit with a 2X4 to understand a idea ..... :D

Thanks again

 

Also I got some other advice from another forum, I built a frame that sits on a 5 Gallon bucket, window screen ... and sift the sand through the screen before putting it in the blast pot.

 

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