Vacuuming the welding chamber

admin

Does anyone have a recommendation for a vacuum that holds up in a pure argon environment? We tried a Dewalt 18v portable but the motor had a melt-down. Figuring it was a fluke, we had it warrantied and it did it again.Edit: We were using a rechargable shop-vac until the battery died. The Dewalt has a hose option that would be great for getting into the tight corners.Last edited by Brainfarth; 10-21-2012 at 11:18 AM.Common sense in an uncommon degree is what the world calls wisdom.
Reply:Look into WELCH pumps. They are used as roughing pumps for vacuum chambers. No problems with Argon either.   Also, GAST makes a pump and you could check into those pumps used by the Tin knockers to purge AC lines for freon. I wonder why the DeWalts dont like Argon?
Reply:I didn't even think about it. We need to clean the chamber of dust and chunks of brick that come off of the furnaces during part moving. Installing a cleaning system is not a viable option, so rechargeable is the direction we went. The reason for the furnaces inside in the chamber is so the parts can go through pre and post heating because it a titanium alloy.Last edited by Brainfarth; 10-21-2012 at 11:50 AM.Common sense in an uncommon degree is what the world calls wisdom.
Reply:I doubt it's the argon but rather the reduced air flow... most vacuum cleaners draw the exhaust air across the motor windings to keep the motor cool. Restrict the air flow in any appreciable way and the motor will run too hot causing premature failure. Insaneride recommendation of a vacuum pump would be the way to go but they are more spendy and heavier than the Dewalt vacuum cleaner.I imagine you could modify the vacuum to draw some outside across the windings but it would certainly void your warranty. Maybe it would be as simple as drilling a few small holes in the hose. You'd lose a little vacuum at the head but it may be enough slippage to keep the motor cool.
Reply:Titanium needs Hi Vacuum. Critical parts could fail. The standard method for Hi Vac would be ; rough out the chamber with a ROOTS Blower then switch to a Diffusion pump or Turbomolecular pump, then weld/melt your Ti. Clean out the condensate in your chamber when necessary. Use shovels , brooms and a Dewalt.
Reply:Originally Posted by BrainfarthDoes anyone have a recommendation for a vacuum that holds up in a pure argon environment? We tried a Dewalt 18v portable but the motor had a melt-down. Figuring it was a fluke, we had it warrantied and it did it again.Edit: We were using a rechargable shop-vac until the battery died. The Dewalt has a hose option that would be great for getting into the tight corners.
Reply:Good point about the airflow forhire but Brainfarth isnt really giving enough information. Probably proprietary reasons. Is Oremet in Portland?
Reply:Those compressed air vacuums are impressive. A venturi or jet makes a vac out of compressed air.
Reply:You got the proprietary right. I have to watch what I say. And I'm with Precision cast parts.I've been looking for an air vacuum and have found a few, but they want too much for what they are. There is an argon hose in the chamber that I could use easily enough. I wish I could just buy whatever I want, but I have to stay within a set budget.Common sense in an uncommon degree is what the world calls wisdom.
Reply:I think everybody (including me) is confused....I think the guys just wanting a vacuum cleaner to clean out stuff before the chamber is even purged, or while it's purged.Has nothing to do with welding in a vacuum, he says he's welding in a pure argon enviroment.Last edited by MikeGyver; 10-21-2012 at 04:55 PM.Welding/Fab Pics: www.UtahWeld.com
Reply:That's the way I read it as well Mike. I don't think he's trying to evacuate the air from the camber to purge it. Only that he needs to clean up debris from the inside to eliminate the possibility of cross contamination from the "damage" to the inside of the oven.If the old shopvac worked well, but the dead battery was the only issue, then I'd look at simply trying to find an appropriate replacement power source. SLA batteries are inexpensive and easy to locate. If you can get 110v power to the unit, a simple transformer would work to make it a plug in model if needed.Part of me is confused with the exact requirements. You talk about a portable vac, and some of this makes me think of a glove box chamber. Then your comment on the heat treat oven makes me think this chamber is a lot bigger than my 1st impression. I can understand the need for confidentiality and "secrecy", but a better idea of what size is involved would help. If clean up is simply the issue, how about some simple PVC piping and a ball valve to seal the tube and use an external vac? Granted the down side would be the loss of argon from the chamber..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:I would open up your bad dewalt shop vac, remove the electric motor and replace it with a pneumatic drill, then power that with argon in order to maintain your argon environment. I think he is using the shop vac inside of a large purged chamber and the argon is insulating the heat in the electric motor melting it instead of conducting the heat away like air would.Dynasty 200DXPassport plus w/ spoolmate 100victor 315c oxy/(act and prop)Miller digital elitemilwaukee power tools
Reply:Thats interesting Turk and I gotta say, your guess gets my vote.But why does the Argon hinder the motor?
Reply:as during welding, it does not conduct the heat as well as normal air, there by letting the motor get hotter and melt downDynasty 200DXPassport plus w/ spoolmate 100victor 315c oxy/(act and prop)Miller digital elitemilwaukee power tools
Reply:I'm sorry for all the confusion, but I was at work typing away on my cracked screen phone. That being said...I weld in a vacuum chamber (not in a vacuum). It is a chamber of gas (argon in my case). Because this chamber is so large (you could easily drive your VW Pop Top Camper Van with the top up into it), it is not possible to dump the gas and bring the internal environment back to spec in under 24 hours. So we have a vacuum chamber attached to it. You can throw your part in, vacuum it down to whatever the engineers say is okay, open the valve that ties the chambers together and wait for the two to level out until you can open the door in between the two.To add to the confusion, there are furnaces involved. So the environment is not only tainted with welding byproduct, but heat as well and that is were equipment failure shows its ugly face most often. What I am after is a battery powered vacuum cleaner (dust buster style) that will hold up in very harsh conditions. I am not sure what killed the last two (maybe titanium oxide dust?), but I need to replace it soon. I cant suck out the dirt and blow it outside of the chamber. I'm not sure the system could keep up with the CFM of a shop vac. I think that would take care of any rodent problem we had in vicinity of the vent pipes though.Last edited by Brainfarth; 10-22-2012 at 01:20 AM.Common sense in an uncommon degree is what the world calls wisdom.
Reply:Pipe in a central vac type system, vac ports on one wall, vac unit outside the chamber, seal ports when not in use.
Reply:I hate to send anyone to the home despot... but, have you seen this?http://www.homedepot.com/h_d1/N-5yc1...&storeId=10051At 25 bucks it would be pretty much disposable.Ian TannerKawasaki KX450 and many other fine tools
Reply:Air is 50% more thermally conductive than pure Argon."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Argon is also more Electrically conductive than air. Its an ion gas and doesnt need Hi voltage like Nitrogen or air.
Reply:I once had a client who needed some remote sensing and alarm equipment.  He was working on a military installation and the details like the quantity were classified.  I told him we could do it no problem, but our price was classified.  No kidding, folks, he wanted a price but couldn't tell me how many he needed.  This was from a dinosaur company, Western Union, back in the day."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:An update: I was going to toss out the old 18v Dewalt vacuum cleaner, when I decided to give it one more try. I charged it, and it fired right up. I'm not sure why the last guy told me that it was burned up. So I threw it in the chamber and started vacuuming. It does okay... From time to time. It was slow down so much that you cant hear it any more, then it will start revving up to a point of concern. What a strange deal.Common sense in an uncommon degree is what the world calls wisdom.