[Grant Nicholson]

I live in Ontario, 2 hours north of Toronto.
Apparently Trupan Ultarlight is the ultimate spoilboard - I can't find it anywhere nearby.
Does anyone have recommendations for a lightweight more porous spoilboard solution that I could get a couple sheets of? I have a 4' x 8' table.
Thanx,
Grant Nicholson

[CNCRob]

Have you thought about using a 4x8 sheet of LDF. Thats what they use to hold sheets of plywood where I work. They just skim down both sides before the first use.

[Grant Nicholson]

LDF - that's a norbord product name isn't it?

Are you using the 3/4" or the 1/2"?

When you mention skimming down the sides, is it because it's coated or faced with something?

I have an Amana surfacing bit coming to shave down the board as I use it (and to get ideal depth).

Thanx,
Grant

[CNCRob]

The LDF stands for "light density fiberboard". They use 3/4", The reason they skim it the first time is to remove the thin coating on the top and bottom surface, Which really increases the vacuum going through it. Then as they use it they will occasionally skim it to remove the cut lines of all the different parts they cut on it. When they do that; they will usually skim the side they have been cutting on then after they skim it they will flip it over because it will usually bow up on the side that was skimmed. (The bowing maybe caused by all the humidity here, were in the south east, united states, although im not sure if thats the reason or not). They will keep repeating the process of running parts and skimming the spoilboard untill the spoilboard gets to about 5/16 or 1/4 inch thick, then they will throw that one away and start the whole process over with a new one. They can usually cut on the same one for a week or maybe a little longer before it ever needs to be skimmed down. I hope this helps- Robbie

[CNCRob]

I forgot to mention, before they bought another vacuum pump they had two of the CNC machines hooked up to the same vacuum pump. They used to put duck tape on all the edges of the LDF to help prevent vacuum from leaking out the edges. Since they bought more vacuum pumps they have more then enough vacuum and don't need to tape the edges any more.

[Grant Nicholson]

Thanks - that's exactly what I wanted to know - I have fairly high humidity, plus only 1 10hp vacuum pump - the duct tape will help I bet.

I've only had my machine (it's full time) for two months, and I'm really eager to get the surfacing bit in another week or so. I've been using medium density mdf, and no doubt there's a 'skin' on the surface. It doesn't take many jobs to scar up the surface and reduce the hold down capacity!

cheers,
G