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Here is the latest Luthier Tips du Jour video - In this video I show how to laminate sides without an electric vacuum pump. This video as well as all my other videos are available via my website, http://www.obrienguitars.com/videos , LMI's website or on youtube.

THat's pretty sweet I've never seen a vacuum bag with it's own pump like that.

I found this video interesting. I know it's about laminating sides, but I was thinking the vacuum bag could be used for top and back braces. I currently use a vacuum pump to glue my top and back braces. It doesn't take up as much space in the shop as a go bar deck. I thought that the 26" x 28" bag would be suitable for top and back bracing, but I wish the valve was located at a corner rather than in the center of the bag...

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

I just realized that the bag would also need to accommodate the radius dish...

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

Or simply one of Josh House's raduis workboards that are guitar shaped...

I wonder if you could ask to have the valve placed in the corner?

You can get a bag big enough from veneersupplies.com that are just the right size for a radius dish. How do I know? I got one and use it for that. Also the valve is surface mounted, so it doesn’t interfere much at all.

One thing Robbie doesn’t use that I think makes a big difference is breather cloth. I know people who successfully use mosquito screen, but I like this:

https://www.veneersupplies.com/products ... shNet.html



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The pump looks like the ones used to vacuum wine bottles after they've been opened. Pretty slick!

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

Take a look at 9:30 in the video. I mention and show using a small piece of breather material around the vacuum intake.

I wonder if a scotch brite pad would work as breather cloth?

Yes, I meant along the entire length of the side. The bag can seal against itself anywhere, not just at the valve. That is how I was taught to do veneering, with either breather mesh or a platen with grooves across the entire piece and I use that technique for laminated sides and plates. To me it is important, but obviously you were able to do a successful lamination with only a small piece at the valve. Nonetheless, I still would recommend the breather mesh I linked to above.

How much vacuum pressure can you achieve with the hand pump?

You are correct. A breather material along the entire surface would probably be best.

I Use exactly that (Josh's workboard) with these bags and it works great.. I think they might move the valve, they are pretty accommodating, but I find it right over the X is not an issue.. Also remember you need to get the air to the valve as the bag collapses..

Also I should say I don't have the new fancy valve Robbie shows mine is the basic one as this new one was not available when I got these..

Also I'm just testing a different method of sealing the bag. I find after a bunch of uses the sealing gasket gets pretty messed up and while it is pretty easy to replace I have not found any place I can buy it locally.. Lee Valley carries it but not stocked in their stores.. So I am trying method 3 listed here WITHOUT any gasket material.. so far it seems to be working.. I literally just tried it tonight!

https://www.joewoodworker.com/veneering/clamps.htm

Anyway bottom line nice product and from my experience a good company to deal with.

Kerry

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My Website http://klw-strings.com
My Luthier's Blog...http://klwstrings.blogspot.com

Claim from their website -

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.