Corian for Vac Table?

[daniel]

Hey Guys, I have a few questions.....

Is Corian and pvc the same material?

Does about a $180 sound right for a 4x8 ft piece that is 1 inch thick?

Would it be a good material for a vacuum tabe?
Thanks again Guys!

[Brady Watson]

Dan,
No, Corian is not at all the same material as PVC.

Not sure on pricing, but PVC would be a great material for vacuum. Keep in mind that you will need a spoilboard/bleeder in addition to the PVC.

-Brady

[sawkerf]

Dan,
Is the $180 for Corian or PVC?
I don't think Corian is available in 1" and a 4x8 sheet of 1/2 would cost a fabricator several hundred dollars, plus you have to be a Dupont certified fabricator to even buy it. Of course, you may have found a way around that. Every time I've tried to buy even a small piece of the stuff it's been very difficult. I would be interested in the PVC for my table though. Where would you get it from? Kip

[scott_smith]

4'x8'x1" PVC in McMaster Carr goes for $538.40

[daniel]

I found 4x8 ft sheet that is one inch thick of pvc board for $180 from a sign supply company in Orlando.
I think I'm going to try and use it for the base of my vac table.

[elcruisr]

Daniel,
that PVC sign board is not solid PVC. It has a "foamed" core with paper thin solid faces. I cut it for sign companies all the time. It is neither as strong or anywhere near the density of solid PVC. It may not be able to hold a vacuum having a porous core although I've never tried.

Eric

[daniel]

Eric, What exactly does "foamed core" mean. I've cut letters out of this board before and it "seemed" to be solid all the way through...

Is there any other kind of synthetic material that is reasonably affordable I should check out?

It seems that the MDF from Home Depot I've been using doesnt work that well...

[elcruisr]

True solid PVC weighs a ton and will cut with a slick shiny surface. PVC sign board will cut with a dull surface and if you look very closely the material is very small celled foam. It's also known as expanded PVC. Most people think sign board is solid but trust me, I've worked true solid 3/4" pvc sheet and it takes two people with some muscle to load it! 1" I'd use my forklift for. Solid also costs about three times the cost of sign board because there's alot more material there.

Eric

[daniel]

Thanks Eric,
The thought did cross my mind that it seemed light compared to PVC pipe.
I guess I'll try something else...

[elcruisr]

You can use MDF as a base, you just have to seal it well to prevent vacuum loss. Two coats of poly and mine's been working for three years.

Eric

[dingwall]

How stable is solid PVC for vacuum fixtures?
Does it move over time?
Does it have internal stresses that would cause it to warp?

I've been using Melamine, sealed on the edges and it works OK, but I think it could be a lot better.

Aluminum would be the best, but won't fit on my VISA. I'm thinking of trying PVC as a second best solution.

Most of my vacuum fixtures are roughly 15" x 22".

[billp]

Sheldon,
Solid PVC is VERY stable. it does not seem to move after months of use. There hasn't been any sign of shape shifting after it's been cut on a table saw, or the 'Bot. I carry a few "pods" made of PVC to all of the Camps, and I think that anyone who has seen the product will agree with me.
I only use material that is at least 1"thick, this is to allow the proper threading for vacuum fittimgs. Anything thinner than 1" will usually mean that once a fitting is inserted the pod will not lay down flat on the table. The surface is great for using gasket tape as well.
I have used an 11"by 18" PVC pod for cutting lithophanes, and as everyone knows you NEED a perfectly stable, and flat base to do them properly.
If someone's table is not as flat as it should be the PVC can still be "fly cut" to achieve a parallel surface to the router/spindle, but I wouldn't take too much off because of the reason I mention above. Plus if you make a mistake and go a fraction too deep on your toolpath you aren't going to hurt your bit.It's reasonably affordable, and it machines nicely.

[mklafehn]

I read that HDPE is a good material for a vacuum base. It is non-porus, very stable and cuts easily. It is pricey, I believe around $180 for a 1"x4x8 sheet. But should last a long time. I plan on using this material for my vacuum system in the near future.

[Brady Watson]

The downside is that it is *very* slippery and cannot be glued reliably with anything that I know of...You want some friction on the surface to keep parts from spinning at the last part of the cut.

-Brady

[mklafehn]

My suggestion was to use this material to cut the vacuum grooves into, then use an MDF bleeder board on top screwed to it. I realize it is very slippery, but because of the non-porus nature you don't have to paint it and it will remain relatively stable throughout it's life.

[evan]

I was told by the guys at TAP Plastics that both HDPE and PVC are fairly stable (although tempeture changes will cause some expansion and contraction) until you surface them, they are likley to cup or warp, because of unequal stress relief. If anyone has better information (not all sales people know what they're talking about) I'd like to hear it because PVC and HDPE are much cheaper than RICHLITE or PAPERSTONE (it comes as big as 1.5"x60"x144") which is what I was planning on making my new VAC Table with.