MDF Screw Up question?

Yes, it does foam quite a bit unfortunately - expands 3-4 X!  Don't be too overly generous with how much you put on - it's not like a contact adhesive like the liquid nails or Elmers.  Make sure you have coverage across the joint but only minimal to acheive that. You can usually keep up with it as it is working - use a scraper and it turn keep that & the piece clean with paint thinner or suitable solvent while it is still not fully cured. It will sand off when it's cured, but the less work you have to do there, the better obviously!

I just think you'll get a better bond with it, especially if you are not using biscuits or something to re-inforce the joint.