some thoughts on joinery

[Marcjwebb]

hi all, so have had some great feedback and responses so far, so thought id fill you guys in a little more to get another question answered,

so basically i work a lot with MFC, and i make reptile enclosures. basically i have spent time and time trying to use dowels to do all my joints which is both time consuming and has been an absolute headache trying to get lined up, let alone flush.

i am currently considering a biscuit joiner, i dont however have a large budget at this moment and looking about the £50 at a push, but my question is ....

is a biscuit joint going to be able to give me flush joined 90 degree pieces, and be strong enough once glued for what is effectively just a large box lol.

Any thoughts here would be fantastic.

Kind Regards

Marc

 

[rafezetter]

Yes, a biscuit will give you the flush joints you want BUT - and here's the important bit - as long as you set it up correctly, and use the same reference faces on the wood. It's not quite as foolproof as people think, but certainly easier than a dowel jig (for my experience anyway as I tried a dowel jig first before buying a biscuit jointer.

You don't need to go as far as £50 for your first machine - I bought one from Aldi and it certainly seems good enough for hobbyist use.

Strength is a different matter - biscuits are purely for alignment, and provide only marginal extra joint strength because the extra glue surface area is small unless you put a bunch of them in, in which case you might as well invest in a router with a drawerlock bit to give you double effective glue surface area.

If the cosmetics of the boxes aren't paramount then you could use biscuits for the alignment, then once the glue has dried drill holes and tap hardwood dowels through to give extra strength. Done well they could even be used as a feature with contrasting woods used.

 

[RobinBHM]

Dowels are commonly used in the manufacture of kitchen carcases made in MFC. The difference is that the drilling is done on point to point CNC machines. Dowels, as you have require a very high degree of accuracy in 2 directions, difficult to achieve manually.

Biscuit jointing only requires accuracy in one direction, a rough pencil mark will do for biscuit spacings. You will find making carcases very quick with a biscuit jointer and it is easily to make carcase edges line up. Ive never tried gluing biscuits on mfc so I dont know how well it would work, probably fine but only the biscuit and slot will bond.

 

[James-1986]

As the former owner of a erbaur biscuit jointer and the current owner of a lamello biscuit joiner, then no, I wouldn't bother!

If it is something that is going to make decent money then invest in a mafell duo doweller or a multi hole boring machine.

 

[Marcjwebb]

My concern is mostly with the joint. When you guys say about strength do you mean that it is likely to pull apart easily or is it just a marginal difference between that and dowels ?

As long as the joint can hold the box together and not fall apart that's kind of what I'm looking for really

 

[Paul Chapman]

In my experience, biscuits will produce a far stronger joint than dowels. A biscuit joint is also far quicker to make and far more accurate than a dowelled joint. If you go for a cheap biscuit jointer, just make sure it cuts accurately.

Cheers :wink:

Paul

 

[custard]

My concern is mostly with the joint. When you guys say about strength do you mean that it is likely to pull apart easily or is it just a marginal difference between that and dowels ?

As long as the joint can hold the box together and not fall apart that's kind of what I'm looking for really

You'll be fine, the biscuit jointer will give you all the strength you need...provided your "reptiles" aren't crocodiles! And if they are crocodiles then just increase the number of biscuits by using 80 or 120mm centres instead of 150-200mm centres and you'll still be fine. Seriously, as long as you aren't making chairs or other highly stressed joints then biscuits are plenty strong enough.

I've used several brands of biscuit jointer and what I've found is that ultra cheap versions are very variable, you might get lucky, you might not. Mid range versions (like Dewalt) are excellent if the sole is always flat against a flat reference surface (like a 25mm sheet of MDF), you'll have to make some simple jigs to hold the workpiece vertically but if you're serious about quality and not bone idle then you'll do it. Top end versions like Lamello and Mafell are super accurate any which way you use them, but until you've had some practise you'll still get the best results with the machine's sole plate flat on a reference surface.

Good luck.

 

[Marcjwebb]

That's brill. Just the answered I needed to know.

Thank you guys. Great help as usual

 

[RobinBHM]

As mentioned above, most cheap jointers will have their blade reasonably parallel to their sole plate (provided it is flat). However cheap jointers will invariably have fences that are not parallel to the blade.

The distance from sole plate and blade is fixed, but it is the correct distance for 18mm thick board.

 

[deema]

Dowels work well, are very cheap and easy to use and the solution is probably a very small investment in a good jig to ensure alignment of the holes. Try looking for the Record 148 jig on the auction sites. I have a couple and they are extremely easy to use with pin point accuracy. I'd encourage you to have a go and if it isn't for you and the seduction of a biscuit jointer is too hard to resist you can always realist the jig and get your money back. Win - win solution, now there's a novelty!

 

[dzj]

Confirmat screws and a stepped drill bit is all you need to make very strong mfc boxes.
(There are plastic caps that cover the screw heads if that's an issue.)