Extira anyone?

[dogfuel]

Has anyone worked with the Extira Product. Looks like MDF but the similarity ends there.

The Manufacturer claims it will not absorb water (I'm gonna break out a postage scale and verify this by soaking a sample). Has anyone (I'd guess it'd be a great sign substrate) cut this using a SB?

I started into a decent sized job with their 1/2" material today today and almost immeadeatly broke a 1/4 Upcut bit (1.3 @ 16k RPM). The top and bottom edges were fuzzy but otherwise the cut was clean.

Before I run through a battery of bits/feeds/rpms, I thought I'd ask if anyone has gone through this - I'd really like to do it in a single pass.

I'll have 24x24 and 24x30 peices left over if anyone wants to pay the postage and has use for scraps this size (first come, first serve so please don't take offense if I have none to send).

[elcruisr]

I've cut up several sheets of 3/4" into sign lettering and done several more with v-carved letters. The customers are happy with it and I am as well.

Can't understand breaking the bit with those feeds unless it wasn't very sharp. I started the job at 2.75"/sec at 12,000 and ended up at 3.5"/sec at 14,000 (I'm running a new PRT Alpha upgrade). I was using a 1/4" single flute compression spiral from Onsrud. Left a nice clean edge top and bottom.

Eric

[alano]

I've cut up a fair amount of Extira myself. Among these: profile cuts, bevel carving, area clear routing, sand blasting, and of course priming and painting. The machining parameters basically parallel those of MDF. My shop floor is concrete (smooth) and the dust produced does tend to make the floor rather slippery.....

The largest project I used Extira on was this monument sign. Everything with the exception of the lettering is Extira. The lettering is sign foam.




Alan
5032

[kerrazy]

Alan,
What are you finishing it with, Latex or oil based finish?

I have had a sheet of extirra sitting outside our shop here since December 18th and it has at some times been subjected to 8 inches of standing water. It is not sealed at all.

So far so good, no noticible change.

Dale

[kerrazy]

I also used a sheet for my ShopBot table as if it does not take on moisture than it should not cup and warp to much? Right?
Dale

[alano]

Dale,

This particular job was finished out with latex. Primer was Jay Cookes.
Alan

[kerrazy]

That's exactly what I was hoping to here, as those are the products I use.

Thanks,
Dale

[donchapman]

How long has Extira been around, is it heavy like MDF, does it hold screws well, how much does it cost, and when do you prefer using it instead of high density urethane?

[gerald_d]

Extira website (http://www.craftmasterdoordesigns.com/pageBuild.asp?PageID=B_ext_e&UserID=A)

After a 24hr soaking in water a 3/4" thick sheet will get 9% heavier and 2% thicker. Very good by "wood" standards.