Vacuum Press Anyone?

[metallurgynerd]

Has anyone else tried using a vacuum (bag) press for at least the initial shaping/forming of holsters? I have a vacuum press setup which is normally used for veneer work (woodworkging) but I've been experimenting with it for forming cases. It's worked out pretty well so far, though you may want to use a bone folder or similar tool to sharpen the impression (as you do with other presses). I'm just wondering if anyone else has done this and if they've learned any valuable lessons in the process that they'd be willing to share?

One of the biggest advantages I've noticed is that I can press multiple items at once. I'm only limited to the size of the bag. I happen to have a two-stage industrial rotary-vane vacuum pump (got if for free!) but you can buy hand pumps that pretty much do the same thing with more effort.

Edited July 20, 2010 by metallurgynerd

[bitone40]

I have tryed it with my vac pump which is for pulling freon out a/c systems ,its a big one and pulls 30 in/hg of vacuum so it works just fine , I dont have a press or table setup or anything like that but I have used vacuum bags for storing cloths , they sell three bags for 9 bucks and I just adapted to make it work , the only problem i had was the bag creasing up and leaving wrinkle marks on the leather , I tried taping the bag to a table to stay put but it kept shrinking to half its size and creating wrinkle marks , I do want to try to make a vacuum table but do not know what to use as the top piece to get pulled (sucked) down to sandwich the leather ,the only thing I can think of would be a thick trash bag plastic , its pliable and streachable, any other ideas

ben

[Ferg]

We use a CNC in our wood shop, Vacuum pump for the table has a ten horse three phase motor, it will maintain 15 to 25 inches of vacuum on a 2' x 4' table. I am dying to try forming some leather on this. LOL

My understanding is that you must leave it in the vacuum for at least over night or about 24 hours so the leather can dry completely.

ferg

[metallurgynerd]

I have tryed it with my vac pump which is for pulling freon out a/c systems ,its a big one and pulls 30 in/hg of vacuum so it works just fine , I dont have a press or table setup or anything like that but I have used vacuum bags for storing cloths , they sell three bags for 9 bucks and I just adapted to make it work , the only problem i had was the bag creasing up and leaving wrinkle marks on the leather , I tried taping the bag to a table to stay put but it kept shrinking to half its size and creating wrinkle marks , I do want to try to make a vacuum table but do not know what to use as the top piece to get pulled (sucked) down to sandwich the leather ,the only thing I can think of would be a thick trash bag plastic , its pliable and streachable, any other ideas

ben

If you're looking for heavy vacuum bags or the material to make your own, the best website I've found is:

http://www.veneersupplies.com/categories/Vacuum__Press__Items/

No, I have no affiliation with the website, in case you were wondering. I've ordered some stuff from them and have been satisfied with their products and service. They sell everything you could possibly need associated with a vacuum press. I already have a vacuum bag sold by Roarockit (intended for making laminated skateboard decks, not that I ever have or would!), but I'm thinking about ordering some of the super-stretchy urethane material from veneersupplies.com and making my own bag. Even with the vinyl bag I have, I've had no problems with the bag wrinkling and leaving marks. One thing that is a big help for vacuum pressing is using a breather mesh that basically provides very small passages for all the last little bits of air to get out of the bag. Only trouble is if you place it over the leather it will leave a diamond-pattern imprint that you might not want (or you might actually like?). So I usually just place a "trail" of breather mesh from the evacuation valve over to the piece of leather all around it's perimeter. That usually does a real good job of getting the air out.

If anyone's interested, I can post pictures of my setup.

[metallurgynerd]

We use a CNC in our wood shop, Vacuum pump for the table has a ten horse three phase motor, it will maintain 15 to 25 inches of vacuum on a 2' x 4' table. I am dying to try forming some leather on this. LOL

My understanding is that you must leave it in the vacuum for at least over night or about 24 hours so the leather can dry completely.

ferg

Hmmm. Hadn't though of letting it dry completely in the press. I would have thought that if you have a good bag with no leaks, it would take a long time to dry since there's no air flow removing moisture. In my limited experience thus far I've found that if I case my leather just like normal, all I need is about an hour in the press and it will hold it's shape very well and can be taken out of the press to dry in open air over night. Like I mentioned you can deepen the impressions by hand with a bone folder if you like right after removing from the press or just take it out and let it dry.

On the subject of vacuum tables, I think I've seen plans online for a DIY vacuum table for veneer pressing using a simple wooden frame and a sheet of heavy polyurethane. Apparently the biggest challenges are getting the frame to be warp-free, the table to be very flat, and getting the right kind of adhesive-backed foam gasketing to seal the frame to the table. If I recall correctly, veneersupplies.com sells the gasket material as well as the polyurethane sheeting.

[ShortBBL]

If you're looking for heavy vacuum bags or the material to make your own, the best website I've found is:

http://www.veneersup...__Press__Items/

No, I have no affiliation with the website, in case you were wondering. I've ordered some stuff from them and have been satisfied with their products and service. They sell everything you could possibly need associated with a vacuum press. I already have a vacuum bag sold by Roarockit (intended for making laminated skateboard decks, not that I ever have or would!), but I'm thinking about ordering some of the super-stretchy urethane material from veneersupplies.com and making my own bag. Even with the vinyl bag I have, I've had no problems with the bag wrinkling and leaving marks. One thing that is a big help for vacuum pressing is using a breather mesh that basically provides very small passages for all the last little bits of air to get out of the bag. Only trouble is if you place it over the leather it will leave a diamond-pattern imprint that you might not want (or you might actually like?). So I usually just place a "trail" of breather mesh from the evacuation valve over to the piece of leather all around it's perimeter. That usually does a real good job of getting the air out.

If anyone's interested, I can post pictures of my setup.

I'd love to see it. thanks!

[metallurgynerd]

I'd love to see it. thanks!

Okay, here's some pictures of my current setup.

Bear in mind that I don't have a project on the go at the moment so I can't show you a piece of leather in the press, but I put a pistol in there just to show you how the vacuum press stretches around it. Trust me, it does a great job squishing the leather down around whatever you put in there. I have one shot with the pistol INSIDE the breather mesh, and one with the breather mesh ADJACENT to the pistol. Either way gives good results, but of course putting your item INSIDE the mesh will leave little criss-cross marks like you see on the picture of the double mag holster. The hatchet holster was formed with the mesh ADJACENT. The plywood board in the bag allows you to stretch from one side only if you want a case or holster that is flat on one side. If you want your holster formed equally from both sides, just take out the board. Both the mag holster and hatchet sheath were formed by the press only without any additional hand forming.

Oh, and the mag holster and hatchet sheath shown are definitely NOT my best work. They were quickly thrown together to test the capabilities of the press, so please excuse poor edge burnishing, crappy stitching, uneven dyeing, etc. I have a Luberto Classic on it's way to my house this week so I can finally do some nice stitching.

My vacuum bag is 13" by about 48" and was purchased from Roarockit. It included a hand pump (that works with the larger gray valve on the bag) and some sticky black mastic to seal the opening. I discarded the mastic pretty quickly and switched to the blue and white plastic clip-type bag sealer. It works great with the added benefit that it isn't a sticky pile of tar. I added the smaller brass valve to the bag myself and it mates perfectly with the brass clamp on the end of my vacuum pump hose.

My vacuum pump is a laboratory-grade BOC Edwards RV12 that sells for about $3000 new. Fortunately I got mine for free from a lab that was shutting down and planned on throwing it in the scrap bin just because they didn't need it anymore even though it was barely used and in perfect working order. It's way more pump than I need for this press, but the price was right! You should be able to get a good vacuum press for well under $300 that will do the job just fine. Or you can order a Roarockit kit for about $50 and it will include a hand pump that draws almost as much vacuum, but obviously takes a little more effort than just flicking a switch! My pump weighs about 65 lb so I plan on making a rolling cart for it (with hose storage of course) as soon as I dig through my plywood scraps and find some suitable pieces.

Anyone interested in learning more about vacuum pressing just needs to start searching online for "veneer vacuum press" and you should find plenty of info.

Eric.

Edited July 21, 2010 by metallurgynerd

[Denster]

The vacuum bag system is all I have used for forming holsters for that last two years or so. I use the more expensive poly bags as the vynal, while it worked OK, did not expose as much detail as the poly and with the poly I bone the detail right through the bag. The bags are virtually indestructable I've done over 2 thousand holsters through mine with no problems.

There is no point to leaving it in the bag after you are done boning. Just take it out flip it over put it back in and do the other side. Then take it out and into the convection oven at 130 deg for a half hour and let air dry.

With these small bags pump size in not terribly important. Mine is only 3.5cfm. Remember it's not the amount of suck but the outside air pressure on the bag that provides the force for forming.

Do a search for vacuum in the holster topic and you will find a detailed post about my setup with pics.

Edited July 21, 2010 by Denster