For mechanical strength the dowel would probably win due to depth but, joint type, material thickness and so much more could make that a long discussion if one were so inclined ;-). Take me to the hotel – Baggage gone, oh well …. 12-16-2016, 10:07 AM #3 I wonder, when exposed to glue, if MDF biscuits would swell, for good or bad. 12-16-2016, 10:16 AM #4 For alignment – no issues whatsoever and they will help to secure the joint. 12-16-2016, 10:54 AM #5. I wonder, when exposed to glue, if MDF biscuits would swell, for good or bad. Biscuits that are too close to the surface can ‘telegraph’ thru to the show surface because they do swell. 12-16-2016, 2:13 PM #12 I am not using biscuits made out of MDF. I am using regular biscuits joining MDF pieces.
Biscuits are ideal for MDF, IMHO. I use biscuits in all my MDF projects. Typically, I use size “0” or “10”, depending on the thickness of the MDF and the stress on the joint. “The biggest problem with strength is prior to glue up. During a dry fitting, you must take special care keep any butt joints from racking. Pieces of the biscuited end will easily break out, if the biscuit is in place. This is especially true of thinner MDF, like 1/2”. After glue up, you are just as likely to crack the biscuit as you are to break out the MDF. The edges of MDF absorb glue very well, and the joints are extra strong with the biscuits in place.
2×1, yes biscuit jointers dont have too many uses which makes the outlay hard to justify. Still i made radiator covers, cabinets and corner cabinets. The biscuit jointer comes out everytime, its an easy cheap and quick way of aligning corners and butt joints.
can you use a biscuit joiner on mdf Related Question:
Can you use biscuit joints on MDF?
I have used biscuits to join 12mm MDF quite successfully. I just wiggle the jointer a bit to enlarge the slot slightly. Not had a problem with joints bulging using this method so I would think that 18mm will be okay. Just be careful of the dust!!!!
How do you attach an MDF board?
Use carpenter’s white wood glue, PVA or hide glue to create joints between MDF pieces. Because of its more brittle texture and being heavier than plywood or hardwood, fasteners, such as nails or screws, should be employed to hold the joint in place as the adhesive is curing.