Extira for exterior crown moulding

[blackhawk]

I am quoting a job for our local college. They are needing to replace about 40 feet of exterior crown moulding on an old building. I made a couple of similar pieces for them on the Shopbot a couple of years ago. That crown was about 1-3/8" thick and 9" wide. I used yellow pine and the first piece warped terribly and I had to toss it. I finally found two good boards and finished the job.

This time the crown they need is 1-3/4" thick x 11" wide. So, a 2x12 yellow pine won't be thick enough at 1-1/2". Plus, I don't really want to work with yellow pine again because of the warp issue. I was thinking about using Extira for this job, since the crown will be painted. I will have to glue up a 3/4" and 1" sheet to get the correct thickness.

Anyone see any problems with this. What about adhesives? The Extira website recommended Titebond II (not sure why Titebond III wouldn't be better)?

[Tom Bachman]

I would think TB 3 would be a better choice for outside service.

[gc3]

i'd go with a balanced core lamination...3 pieces of the same thickness you may have issues with the extira wanting to move towards the 3/4" side...

tb2 is more flexible...tb3 we gave up on too rigid under temp changes for exterior work

[Tom Bachman]

Is TB 2 moisture resistant enough for outdoor use?

[Brian Harnett]

Is TB 2 moisture resistant enough for outdoor use?

When Tightbond 2 came out over 20 years ago I made some test glue ups out of mahogany and teak, and put them outside they are still outside and all are fine.

It also survived the 2 month dishwasher test

[blackhawk]

Thanks guys, I believe that I have decided to go ahead and do this in my Woodmaster and buy a set of knives. Even though they only need 40 feet, the estimate in Aspire came out to be about 30 hours of machining. 6 hours for each 8 foot piece.

[kurt_rose]

I just can't see 30 hours. Must be all 40'. Still seems like a lot. Well atleast you can add the knives to your collection on their dime.

[blackhawk]

Kurt - Yea, that was for doing all 40'. 6 hours per 8' piece. That was based off 3 in/sec cutting speed. Plus, to get the detail, I would need to use a 1/8" ball nose in a couple of areas. That time includes doing that also.

[Tom Bachman]

When Tightbond 2 came out over 20 years ago I made some test glue ups out of mahogany and teak, and put them outside they are still outside and all are fine.

It also survived the 2 month dishwasher test

That would be good enough for me.