# How long in vacuum press?



## mark4345 (Oct 7, 2011)

How long do you typically leave the vacuum press going? Usual clamp time 30 mins to an hour?


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## AlaskaGuy (Jan 29, 2012)

I don't know a lot about vacuum pressing. But I'm betting those that do will want to know,

What glue are you using?
What materials are you gluing?

Stuff like that.


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## mark4345 (Oct 7, 2011)

Good point. Titebond 3, i am gluing a 1/8th inch piece of mahogany to timberstrand. 
I'm building a front door and using the timberstrand as the core


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## AlaskaGuy (Jan 29, 2012)

The web site says yellow glue is not the best for veneering.

http://www.joewoodworker.com/veneering/glues.htm

Found this on another web site.

Glue Type Drying Time

Yellow Glues 1 to 4 Hours Small pieces (braces on the inside of a guitar can dry in as little as 20 to 30 minutes. 4' x 8' panels can take as long as 3-4 hours.

White Glues 2 to 6 Hours Gives more open time than yellow glues.

Urea Glues 4 to 6 Hours Urea glues need to be at 70º or higher for proper curing and the piece 
should set over night before machining

Polyurethane 1 to 6 Hours Depends on manufacturer and conditions

Epoxies 5 min to 24 Hours Epoxies are two part systems where a catalyst is added to cause it to harden. Most allow you to control the set time by the amount of hardener that is added.

1/8 thick veneer is border line of being to thick from some points of view.

I thinking you need to do some more research before proceeding. Again I'm not a expert but just giving an opinion from some of the stuff I read about veneering.

A good place to start is http://www.joewoodworker.com/


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## wapakfred (Jul 29, 2011)

I always use an urea-formaldehyde glue, and leave it in overnight. If I ever do use PVA, I'd probably go with something along the lines of what AlaskaGuy suggested. Whatever you do, you don't want to rush it, you can screw it up taking it out too early, but it won't hurt to spend a little extra time in the bag…..I really think 1/2 hour is rushing it.


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## bonesbr549 (Jan 1, 2010)

> I always use an urea-formaldehyde glue, and leave it in overnight. If I ever do use PVA, I d probably go with something along the lines of what AlaskaGuy suggested. Whatever you do, you don t want to rush it, you can screw it up taking it out too early, but it won t hurt to spend a little extra time in the bag…..I really think 1/2 hour is rushing it.
> 
> - Fred Hargis


+1. What he said. If you remove early you can get a bubble.


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