Stave Core Veneer Door Layup

A discussion of vacuum-bag veneering and other construction tips for veneered stave-core doors. July 13, 2010

I have a bunch of interior doors to build using the stave core method. I haven't built any like that yet. I am planning on using poplar core and then gluing 1/4" veneer on each side. I am thinking about getting a vacuum bag for gluing the veneer. If a guy had a big enough bag I could glue several parts at once. I was also thinking about putting a strong back in the bag to keep the styles as flat as possible. I am thinking about using TB II for the glue up. Does anybody see any problem with this process?

Forum Responses
(Architectural Woodworking Forum)
From contributor M:
Youíre pretty much on the right track. We produce our core with finger joint staves to aid in stability. Vacuum bagging is definitely a viable option if it is set up properly and can yield good results.

From contributor S:
When you say poplar core I assume you are laminating plies or purchasing quartersawn? The Vac bag works well, but if you have a large quantity it will take a while. I do five at a time and thatís very easy (one man shop setup). Many stack them multi levels high. Your speed stuffing the bag is the only factor that will affect how many you can do at once. Thicker veneers move around far easier than 1/42" thick veneers, so it is a bit of a nuisance to get it all located in the bag correctly with all of the cauls or plastic. TBII works fine, but donít be too skimpy as dry spots will lead to call backs.

From contributor P:
Why use 1/4" veneers? 1/8 or so should be enough. TBII creeps badly. The only glues that would be worse are TBIII and contact cement. I would use Titebond original or better yet super Titebond which is only available in 5 gal or larger but is much better glue. The best glue would be plastic resin glue - no creep and no rush filling the bag. The biggest drawback is the cure time (overnight if warm).

From the original questioner:
Thanks for all of the advice. I am going to make sure the core is quartersawn. I had somebody else mention using plastic resin glue. Being a one man shop it should reduce creep and increase my open time. Is there a PR glue that stands out as being better than the rest? The reason I am using 1/4" veneer is that is the smallest my planer will do. I have been doing some experimenting with resaw blades trying to get a nice enough finish to be able to use the pieces from the bandsaw. If I get to that point I can use something thinner. Contributor M - is there a reason you are using pine cores? When I started researching doing stave core door a lot of the SC part suppliers were using poplar. Now when I look around I see some are using pine like you.

From contributor M:
We use other woods for core, but you are right that pine is our primary wood. We produce engineered door parts as a mainstay of our business and need to cater to a wide variety of clients. The need is for a wood that is stable, has good interior and exterior properties, availability, and lastly cost effective. Pine has a proven track record of filling all these requirements optimally.

While poplar has it's positive attributes, it is not a reliable substrate for engineered door parts across the board, meaning it is prone to movement and does not do well exposed to exterior climate extremes. I know there are proponents of its use here on the forum, and in a handpicked, hand worked, small run basis it probably is fine. Another difference is we do not produce any core with continuous wood running the full length of the stile solely for the fact we don't want any one piece influencing the performance of the part. Meaning if I was to use poplar, we would chop it in to blocks, finger joint, mould, and re-glue in to core.

I don't believe you have said whether the doors are an interior or exterior application, but that may have some bearing on your core choice.