Phenolic for vacuum top

[pjohnsonj]

Sorry for the repost. I originally posted this in general folder, but just realized this is where the post should be.
Does anyone have any ideas on what the best black phenolic to use for a vacuum top is? Not sure what type Camaster uses these days. Seems like a lot of different varieties, paper, canvas, utilities grades, etc. Can anyone point to a link? Also, does HDPE move too much with temperate changes? Thanks in advance!

[gtgmarine]

Have you tried contacting CAMaster with this question? That may be a lost cause but worth a try.
As for HDPE, let's call it King Starboard... I've heard it could work as a vacuum plenum but never tried it myself.
It sure is a dream to cut and while not cheap, it's gotta be less $$$ than the high grade phenolic.
It's slippery stuff however so if I used it I would screw down my MDF spoil board... just my $0.02.
Good luck.

[tmouse]

I use 25 MM sintra for my Plenum. You do have to skim the top to get the Tite bond III to hold it.

[james mcgrew]

I use 25 MM sintra for my Plenum. You do have to skim the top to get the Tite bond III to hold it.

You have given me a good idea !! can we get it in 5 x width ?

[Doug S]

I just changed to a new type of MDF called DOUBLE REFINED, which is essentially a waterproof MDF that is very dense and heavy. IT DOES NOT BREATHE.
I found this by pure accident when they sent it to me as a spoil board. I glued it down and it did not do anything. I had to mill off the entire board and replace it.
Now my plenum is rock solid and does not move with the humidity at all.

[james mcgrew]

Double refined HDF is what we use for doors and panels. LDF is what we use for Spoil Boards, (AKA bleeder boards) Brand names like Trupan.

[Jim Becker]

The glues used for exterior rated MDF are not going to be compatible with pulling air through the material for sure. Stick with the lightweight MDF...it should be easy to source from a "real" sheet goods supplier.

That said, the exterior rated MDF is really nice to "make stuff" with, however. I did a large set of victorian corbels for a client a couple years with that stuff and the scraps have gotten a lot of mileage around the shop, too.

[Doug S]

To clarify my comments, the DOUBLE REFINED was used to cut the new plenum, followed by a standard MDF for the bleeder board.
This directs the vacuum thru the standard mdf as it is supposed to.
Jim, you are right-nothing goes thru the Double Refined stuff. Perfect plenum material.

[james mcgrew]

I am going to replace my 12 year old plenum soon, I like phenolic on my machine with popo up pins yet not on the Camaster which does not. i will be using 1" hdf on that plenum my machine is a 5 x8 so thicker makes for span, on smaller machines 4 x 4, 2 x4 Etc. 3/4 will work fine

[msimmons]

I was given this contact by Camaster a year ago, as their phenolic source:

www.agrfabricators.com
904-733-9393

It is a 1" x 61" x 121" fiber phenolic.

[Charlie_L]

The original post asked for how much HDPE changes sizes based on temperatures. Here you will find a pdf file used to calculate the expansion of King ColorCore HDPE products. It does have significant size change in length and width that should be considered for the application.

[james mcgrew]

Charlie I have several full size dheets of HDPE here in the shop along with a few 5 x 8s of phenolic, I am not sure i would consider HDPE. I did put it on a 10 foot machine once and work material move so easy i took it off