Blasting: How do you keep your sand dry?

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2015: Blasting: How do you keep your sand dry?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Monday, April 06, 2015 - 05:55 pm:

It is supremely aggravating having to quit because of wet sand clogging the hose, as I did this afternoon. The set-up is this: I have about 65 feet of half inch pipe from the compressor to this filter where the hose to the blaster connects.


There's another fifty feet of hose on out to the blaster, which has another filter on it. Obviously my equipment is inadequate, or I'm not using it correctly. Any ideas?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jack Daron - Brownsburg IN on Monday, April 06, 2015 - 06:13 pm:

Steve,Try adding a low point bleeder between the line and your filter. These are easy enough to add,a "T",short coupling and a longer bleed pipe@12 inches with a step down and a radiator drain cock in it.The problem ,several times a year is the moist air which allows moisture to condense in the line. You ay have to drain it often.They sell commercial driers,but they are pricy.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Hatch on Monday, April 06, 2015 - 06:15 pm:

First, remove the street ell, install a tee there and add a pipe going down with a valve on it to catch water. Next, follow the pipe feeding the air up and where it comes off the next pipe, install a tee there WITH THE OUTLET POINTING UP. This way any water there will pass by your drop and go to another drop pipe with a drain valve on it. Look back at all your pipe and think like a drop of water wanting out of it and give it places where it can get out before it gets to your tools. Dan


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Monday, April 06, 2015 - 06:25 pm:

You know, you've got 2 in-line filters before the air gets to the blaster. My question is what is the condition of the sand? You can filter incoming air 'till you're blue in the face but if the sand is wet/damp.......


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Leck - Ohio on Monday, April 06, 2015 - 06:27 pm:

Steve, a lot of the water is likely condensing in that long run of pipe from the compressor. The warm, moist freshly compressed air cools and the water drops out as it travels out to your hose connection. If your tie-in is a low point, it will all run to your filter/separator. If the filer does not dry the air completely, more condensate will drop out through the regulator pressure drop and you might also be getting a Joule-Thomson effect cooling and condensing water at your hose connection. From there it goes right to your blaster. A simple modification to try would be to move your filter/separator close to your blaster connection instead of in the middle of the run.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Monday, April 06, 2015 - 06:29 pm:

You know, you've got 2 in-line filters before the air gets to the blaster. My question is what is the condition of the sand? You can filter incoming air 'till you're blue in the face but if the sand is wet/damp.......


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary London, Camarillo, CA on Monday, April 06, 2015 - 06:47 pm:

Steve;

Take a look at this diagram from the TP Tools website. It shows a lot of what is being explained. When I ran the air in my garage I followed this model and it has worked pretty well.

Are you running a single stage or two stage compressor? Does it have high recovery? I have a single stage and the recovery is not great, so the compressor runs hot, so the air is hotter, so I have more condensation issues... but the idea of having long metal pipes to cool the air works, but you do still need drains at a couple of low points. Also drain the tank on your compressor regularly.

For painting I use a final disposable filter at the gun, but I don't think that would work well for blasting.

http://www.tptools.com/Modular-Metal-Piping-Kits,2035.html?b=d*8092


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Monday, April 06, 2015 - 07:10 pm:

Here is the diagram. :-)

piping


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Williams, Humboldt TN on Monday, April 06, 2015 - 07:38 pm:

When air is compressed it is heated. Hot air holds water as a vapor. Hot moist air mixed with sand will clog up your sandblaster. To be able to have good dry air to sand blast with you must cool the air so the water will go back to a liquid state. Then it can be removed from the air. Below is a picture of my air dryer. You will see a 1" metal pipe attached to the back wall that is coming from the air compressor. The air goes into the black 55 gallon drum which has 100 feet of 3/4" copper coiled in it and the barrel is full of water. from the black drum the air goes into the side of the blue 80 gallon storage tank. When the air goes into the side of the blue tank is has been cooled and the water vapor is now in liquid form. The water falls to the bottom of the tank, which I drain when needed. The cool dry air goes out the top of the blue storage tank through another filter which catches any remaining moisture. Then the dry air goes into the blaster which you see in the foreground. You also have to have good dry sand. I dry the sand by pouring it out onto the concrete floor of my sandblasting room. The concrete will suck the moisture out of the sand in a few days. Works perfect.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Monday, April 06, 2015 - 09:28 pm:

I'm pretty sure the sand isn't the problem. It seems mighty dry. I'll try the easiest steps first, adding some low-point traps to catch and drain the moisture. If there's still a problem after that, I'll try the moonshine still. :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Rich Chillingworth on Monday, April 06, 2015 - 10:13 pm:

Every now and then I put a trouble light inside the blast cabinet down on the blast media and let it warm the cabinet up for an hour. This raises the media above the dew point and dries it out. Glass beads like to clump when not dry and this simple fix works well.
Rich C.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George n Los Angeles CA on Tuesday, April 07, 2015 - 03:01 am:

When was the last time you drained the tank ?? To keep tank from rusting bleed and open drain cock and let compressor motor run for a few mins to dry out the tank.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Wednesday, April 08, 2015 - 08:34 pm:

It occurred to me that if a short piece of pipe would be a good moisture trap, a thirty gallon tank would be even better.


When my old water heater went belly up this winter, it was the burner control that went south. The tank was good. So that's my new sand blasting moisture trap. So far so good. Not a bit of clogging trouble today.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Wednesday, April 08, 2015 - 09:02 pm:

You're going to love your recently acquired blasting cabinet for the smaller parts, no more hood or breathing vacuum cleaner exhaust air! :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Moorehead on Wednesday, April 08, 2015 - 09:21 pm:

Steve, are you actually operating your blaster in your bare feet?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Verne Shirk on Wednesday, April 08, 2015 - 09:36 pm:

As an engineer that worked around large power boilers (pressure vessels) for many years, I would not definitely NOT recommend using a hot water tank, new or old, as an air tank. I have read where people have done that but I would say that it was not designed for that purpose. 100 psi of water pressure is not the same as 100 psi of air. Water is not compressible and air is. It brings to mind what we were told about in engineering school. A group of engineers were testing a tank. I think they were going to like 1-1/2 times or more over the normal operating pressure to verify the integrity of the tank. It failed catastrophically. There was loss of life involved. I don't remember the details but I did get the concept! Testing of tanks should be with water in case of failure. A tank, such as the one on a compressor, should have an ASME tag on it. There are specific design criteria to follow when designing an ASME tank.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Wednesday, April 08, 2015 - 09:36 pm:

Yep, Mom would be mad if I did it in my good school clothes. :-) Actually, the old overalls I wore for this have big holes in the knees, so it was boots off to keep them from filling up with sand.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stan Howe Helena, Montana on Wednesday, April 08, 2015 - 11:54 pm:

Good advice, Vern. Also, not that Steve is doing it, but never run air lines in your shop with plastic water pipe. I've told this before but years ago when I built my new shop I ran white plastic pipe all over for air. My brother told me not to. I did it anyway. I was on the road with auctions and playing music in those days, one of the guys working for me went back in the shop, turned the compressor on and aired up a tire on a trailer, didn't turn it back off. When we got back after being gone for several days there were shards of plastic all over the shop, the compressor had run non stop until it locked up, fortunately the breaker had popped so it didn't heat up anything to start a fire. I don't know how long it ran but it was still warm when I put my hand on it. Not hot but warm. Had that line blown when we were in the shop no telling who could have been badly hurt or blinded. That was at least 20 years ago and I still occasionally find a little shard of white plastic. I redid all the air lines with black iron lines.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Thursday, April 09, 2015 - 12:22 am:

Hmmm... I do use black iron pipe, but I guess I'd better find an air tank.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jack Daron - Brownsburg IN on Thursday, April 09, 2015 - 12:47 am:

I used schedule 80 plastic pipe on mine,except for the first 10 foot.It is black pipe. You get a lot of heat from the compressor and the black pipe lets line cool down before the plastic .In 25 years,I have blown one joint apart.I didn't get enough glue on it. Schedule 80 has a very high ASTM rating I do run low point bleeders and I am below 100PSI from compressor.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Peter Kable - Kiama NSW OZ on Thursday, April 09, 2015 - 02:41 am:

Steve, One more thing I notice you have very long hoses (especially the red one) there is considerable pressure drop the longer the hose is.

Use the biggest pipe or hose diameter you can and keep it as short as possible.

One demonstration we used to show students what happens was to use a long 1/4" hose with 100psi at the beginning, by the time it got out the other end there was so little it was hard to tell it was there

Look up air pressure drop there are charts showing the amounts involved depending on ID and length of hose.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Eugene Story on Thursday, April 09, 2015 - 06:17 am:

A guy I worked with years ago took a old water pressure pump and used the tank for a air pressure tank. He also lived in a hugemongus two story house. He took the screens out of the house to put storm windows for winter. He had a row of screens about 8 feet long at the end of the compressor tank. The end blew out of the tank and went through all the screens. If blood is brown and lumpy he was bleeding to death.
Gene


Top of pagePrevious messageNext messageBottom of page Link to this message  By Justin H. - Western PA on Thursday, April 09, 2015 - 07:17 am:

For those mentioning how bad of an idea it is to use a hot water tank as a pressure vessel, I agree but I believe that Steve is only using it as a trap and not to hold pressure. I think it is a clever idea and it even has a drain valve at the bottom.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Thursday, April 09, 2015 - 10:27 am:

I used to try and remember to drain the water off my air tank at the end of each day but often forgot. Then I found there was an electric valve thingee on a timer that I bought from ZoroTools. It installs in the drain line out the bottom of my 80 gal tank and it is piped outside under the outdoor stairs to my shop and is aimed to the ground out there. The electric valve timer thing opens up for about 30 seconds each time my compressor kicks on. I have a 5 HP 2 stage compressor. The tank is now dry and almost no vapor comes out each time it kicks on now. I also use iron pipe for all the runs to my various air outlets in my shop. At the outlets I typically have a water separator and regulator at each outlet. I followed the piping rules shown in the diagram posted in this thread. My sand blast cabinet air is very dry as is my paint room air. The problems I have is that the IR brand air regulators that I have seem to get stuck if not used regularly. I am going to switch them out for Parker brand units which seem to work much more reliably.

Just my .02


Posting is currently disabled in this topic. Contact your discussion moderator for more information.
Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration