Synthetic Countertops as flat surface?

[kinghong1970]

not sure what's called, but instead of using mdf, if readily available, how would
synthetic counter top materials work out?

in my cncrp 2448, i was thinking of using mdf as spoilboard... but recent renovation project may give me access to LG Hi-Macs synthetic granite slabs to create a flat and level working surface

according to vendor, this is machinable by router so it can be leveled flat
and also stronger than mdf...

and even at a loss of Z clearance (which is not as critical for my initial needs) i can always add layer of 1/2" ~ 3/4" mdf as spoilboard...

thoughts?

Al

ps, they do come in some nice colors too!

[BanduraMaker]

Before you spend any money, you'll want to investigate whether the material will cup after surfacing. See if he'll get you a scrap you can surface to check out.

I use something called Starboard for my vacuum fixtures and it machines great but, it cups terribly after surfacing. In my case it's not a problem as I'm bolting it to an Al table top which pulls it flat.

[kinghong1970]

i have a 2"x2" sample block, it's available only 1/2" thickness...
seems to drill clean, chipping on the backside but according to the vendor, they can be surfaced, edged or cut by using a router...

not sure if they sag over time... i saw your other post about starboard that bows when surfaced...

i don't have alum plate to mount onto, was hoping this can be used in place of an expensive alum mic-6

or should i just stay with 3/4" mdf that's supported every 13" on X and Y cross members?

[JerryBurks]

I am not familiar with this specific material but all plastics have at 5-10 times higher temperature coefficient of expansion than typical metals and wood. The countertop plastics are usually heavily loaded with more inert filler substance but I would still suspect it is much higher. Depending on how you mount it to your frame a small temperature change may already make it bow

Similarly, the stiffness of plastics (without fiber reinforcement) is usually pretty poor, lower than MDF and much lower than plywood. If you don't need something waterproof and cut resistant, you may be better off with MDF or plywood.

You can compare materials here (example MDF vs. PVC):

Compare Materials: Medium Density Fiberboard (MDF) vs. Polyvinyl Chloride (PVC, Vinyl) :: MakeItFrom.com

[ger21]

HiMacs is like Corian. It's not flat, not very rigid, and expands a lot with temperature changes. If mounted rigidly, it can crack with this expansion and contraction.

[RossMosh]

He's talking about something that is comparable to Corian. It's solid surface material.

You can absolutely use this as a surface material. Thickness can be an issue. Another issue is you can't screw into it. If you do, there is a chance the material will split and crack. Fiberboard is also easier on tools if you do happen to make a mistake.

[zool]

Solid surface material such as Corian and HiMac expand and contract significant amounts. That is why they are mounted on a substrate with silicone adhesive. The substrate has to have large cutouts in it so the solid surface material is not in continuous contact.

Also, Corian and its like are very very expensive, as are the proprietary adhesives that are used to glue solid surfaces at their edges. Getting edge joints tight is a religious experience; to get clean joints vacuum clamping pods are used and clamps are affixed to the pods to draw the solid surface edges tights.

Solid surface materials will crack in an instant. I have helped move large Corian counter tops. On one we built a box for the counter top from plywood and 2x4s to hold it rigid. Move it at night so we could drive slowly and no jostle it in transit. A dozen grown men held their breaths for hours. Got it in with no problems.

I have heard of Corian countertops cracking when a frying pan has been dropped on them. It a bit were to run into a solid surface top, I am sure the solid surface top would crack instantaneously.

Plus, when solid surface materials are machined, it smells horrid, it makes a mess worse than MDF, plus we always wore powered respirators when machining it; sawing or routing.


For what a sheet of solid surface costs, you can buy dozens of sheets of MDF. Plus you will sleep better at night.

[kinghong1970]

well, i guess HiMac is out then...

thanks for the replies.

[louieatienza]

I agree with the others here... I used to fabricate Corian countertops, and like most solid surface materials, you have to allow for expansion/contraction by using a flexible adhesive to affix the stuff to a substrate. Which leads to the other problem with the stuff - it's not strong enough to support itself and must be affixed to a substrate. We'd typically stack two extra layers about 2-3" wide to build up the edge, and leave about 1/8" between that edge and the substrate. Finally you cannot screw anything into it. When we had to, like temporariy mounting a sink or bowl, or needed blocks to pull a butt joint together, we'd hot-melt glue scrap block of wood.

Nowadays, I think they don't recommend cutting with a saw, and if so, the edge should be cleaned with a router to remove any potential stress areas. They used to sell the adhesive in packs where you would break the seal separating the resin and hardener, attach teh pack to an orbital sander to mix the pack, then cut a corner off to apply it. Now you have to use a gun that costs over $500, and the glue comes in a cartridge...

You had to be a licensed fabricator to buy Corian. I sent one of my guys out to attend the "course," but we were buying the material from another shop for years before that...