MFT Axminster Valchromat replacement top

[Roseland]

I've been looking at getting one of these:
http://www.axminster.co.uk/ujk-technology-hdf-valchromat-top-for-twist-dogs-102538

I'd like to get a top that sags less than the standard Festool insert.  The flex modulus of Valchromat and HDF are very similar, but I don't know if Valchromat sags less over time.

Also are the Twist Dogs better than standard dogs?

I'd appreciate any feedback anyone can give.

Thanks in advance,

Andrew

 

[pingvinlakrits]

For that size of a board insert I think you will be perfectly fine with both HDF and Valchromat. There will be little to no difference between them even if you were working in a shop/location with pretty severe seasonal changes.

If I was to work in a shop I would not worry at all and if I had regular field work I would have a dedicated rough and tough portable workbench for that. 

I don't know the long time perspective on using twist dogs. If you were to twist the dogs in the same hole over and over again - would the hole/pattern eventually wear out or develop slop?

I like the simplicity of the good old round hole. I have had zero problems with slop with the bench dogs in the standard mdf holey board. I don't remember which ones I bought, perhaps it was Veritas. Also I use clamps now and then and I would probably damage the twist dog holes to some extent over time if I had that board.

 

[Roseland]

Thanks for the feedback.

I had understood the Festool MFT tops were HDF, not MDF.  And over time they sag, even if left without heavy weights on them.

Baltic Birch Plywood has three times the modulus of Valchromat/HDF, and I'm tempted to try that.

The other material I'm looking at is Medite Tricoya, which is made from Accoya chips/dust, and so should be much less prone to swelling and shrinking.

Anyone else care to comment?

Andrew

 

[Michael Kellough]

Yes, Baltic birch ply is stiffer than MDF.
That stiffness will make it that much more difficult to make it as flat as MDF.

In use, the slight sag of a stock MFT top is rarely an issue.

Many people use the top as a general purpose sacrificial work surface
so the top gets flipped over long before sagging becomes excessive.

 

[Svar]

If sagging is an issue, screw a pice of aluminum angle across the bottom.

 

[Roseland]

Thanks for the suggestions.

On one workbench I have the top as 3/4" ply with stops of 3/4" ply going across under the top between the dog holes.

I'd rather not have to brace the top as it mars the surface if and when I want to flip it over.  I'd rather find a material that doesn't sag to start with.

Axminster's site doesn't have much in the way of reviews of their Valchromat tops; perhaps I'll just have to ask them when next I'm there.

Thanks again,

Andrew

 

[Bob D.]

I would like to try a piece of phenolic plywood. Only issue I can see right off is it may cause problems when clamping items to the table as the phenolic ply with it's hard smooth finish would not have the 'grip' that MDF or Baltic Birch ply does and the workpiece may have a tendency to slip which could be dangerous.

Has anyone tried using this and if so what were the results.

 

[Svar]

I'd rather not have to brace the top as it mars the surface if and when I want to flip it over.

Put a strip of soft felt under it.  [poke]
And I thought I was obsessive compulsive. It's just a disposable work top.