Joints in chipboard - are biscuit joints suitable?

Hi,

Can those of you who have used biscuit-joints in chipboard kitchen cabinet carcasses please tell me about your experiences?

I am going to be building cupboards shortly, and am trying to find out whether biscuit joints are suitable.

With kind regards,

Kevin

I'd suggest pocket hole joints. As long as you can put them where they aren't visible (on the inside for instance), they are much easier, as the whole thing is just screwed together. Very strong joints too.

You'll find a good article on our website:
www.tritonwoodworkers.org.au
Go to the members projects section and you'll find an article by Stuart Lees on constructing his new kitchen using this method.

I'd definitely second that. I've put together a kitchen cupboard myself (MDF based), and pocket holes were excellent in that application.

Biscuit joints are totally unsuitable because of their method of creating a tight bond with the parent material is to expand. This would be fine in mid-panels where the biscuit is expanding against a lot of material, however the edge of panels (ie the other half of the joint) is into the edge, and it is attempting to split the board in two, which is very easy to do with particle board (just try using a chisel to see how easy it is!). The glue is all very well, but a lot of the strength of a biscuit joint is in this mechanical bond.

For those who doubt that, try cutting a biscuit slot (tight fitting), and instead of glue, dunk the biscuit in water (almost sounds like milk & cookies!) and quickly insert it into the joint and wait a while for the biscuit to swell. Then see how tight the joint gets. It won't be perfect (ie locked solid), but it will give an excellent indication just how much the mechanical potion contributes to the overall effectiveness of the biscuit joint. For interests sake, you can also try this in particle board, and see if it makes any difference.

As Stuart says biscuits +white glue = expansion which may cause damage to panels. But biscuits are darn quick and excellent for aligning materials. I use epoxy resin with them - I know, I'm a bad person for doing that - but expansion problem is eliminated and i still get benefit of alignment. And epoxy is such a good gap filling glue that it creates a very strong joint. Plus you get more working time (very useful).