Thicknessing MDF

[Giff]

Has anyone put MR MDF through a thicknesser ? Are there any good reasons not to ? Geoff

 

[o0dunk0o]

Apart from killing your planer knives making huge amounts of dust and noise the finish will be terrible and it may compromise the structural integrity of the board.

Have to ask why you want to do it?

 

[MickCheese]

I am not very H&S conscious but I wouldn't put MDF through my thicknesser as the dust would be horrendous.

There are so many different thicknesses available off the shelf that I would alter my plans to accommodate rather that try to thickness a board.

Mick

 

[Chrispy]

Have you tried it, yes it works ok no it doesn't make loads of dust, (thats what the extractor's for) yes it knackers the knives, and may not stay flat afterwards. I now prefer to sand to thickness if possible.

 

[Giff]

Thanks for the replies. It is for zero clearance inserts to fit into a spindle moulder rebate and although I have previously glued pieces I have had to sand them to get them exactly flush as a tiny protrusion stops the timber or "rattles" it. Geoff

 

[JakeS]

It is for zero clearance inserts to fit into a spindle moulder rebate and although I have previously glued pieces I have had to sand them to get them exactly flush as a tiny protrusion stops the timber or "rattles" it. Geoff

Could you not start out with a stock thickness which is thinner than necessary and put shims or screws in to raise it to the correct height? Like that you could just cut your inserts from a sheet of readily-available material and not have to worry about thicknessing them exactly at all.

 

[Jelly]

For a long run, you'd want to use knives intended for highly abrasive materials... however, If it's just enough to make a fence, you shouldn't have too much trouble with you normal setup. Please wear a good dustmask or half mask respirator though, because the dust is especially bad for you even if the extraction system is functioning well.

 

[jasonB]

Assuming the insert is only supported around its edge why not use a standard thickness and then run a bearing guided rebate bit around the edge and adjust the depth until you have the insert sitting where you want.

As Chrispy says it can be done but as you are taking the denser surface layer off one side it does make it more prone to warp with changes in humidity

 

[andersonec]

Glue a piece of cheap pine on one side of a thinner piece of MDF the plane or sand the pine side.

Andy

 

[Giff]

Great idea Jason I hadn't thought of that. That would work and I could use thicker MDF in the un-rebated part which would be more stable as well. I missed that one !
Thanks Andy another good one. I think I that will help will keep my planer blades intact as well ..
Geoff