I am just wondering if there is a particular type of glue that works best with MDF? I wasn't sure if normal wood glue (if there is such a thing) will do, or will the MDF just suck it up?
Just incase anyone was wondering, I am re-building the amp on my surround sound system (and seperaring the amp from the sub), as far as I am aware (have been told), MDF is a better material for this.
Also, while I am asking this, what is the best finish to use that will give a nice glossy finish? Is varnish ok?
Not entirely sure about the finish but, as you suggest, MDF is very porous and will instantly soak up anything that it comes in to contact with. Therefore, it's probably a good idea to apply a sealer coat (or two) first - Rustins' do a superb water-based "MDF sealer". It should be cheaper than any other 'sanding sealer' and it will seal the MDF quite well.
PVA should fine but, again, you'll probably find the MDF will take a lot of it in, so it may be a case of lightly coating both surfaces. PVA is probably best because of its longer open time, although you can also buy five-minute PVA from Wudcare (search eBay or Axminster).
Now. First glue, any PVA will work well enough, but I prefer Titebond II or III. I assume you are using veneered MDF then any normal finish system will work well but it will depend on the veneer species. If you are going to varnish plain MDF I would advise using MDF sealer (white) then regular paint , I usually use a small foam roller and get super results. Varnished MDF is a bit dull for a living area. MDF is very dense and I suspect ideal for speaker cabs, I've made lots of draws tables desks etc. from MDF painted as discribed and they look great.
I am using plain MDF, no veneer so I try and grab some sealer and find some nice paint.
I will see what I can find in B&Q tonight. Its probably not the best place, but it will be open and I got a voucher from our work wimbledon sweepstakes .
I have used PVA, extramite and polyurethane glues with MDF with no sealer and all glues work well. If you use sealer it may not allow the glue to work as the glue wont penetrate the MDF, and is unlikely to bond. PVA is probably better than than most glues as it has a short open time and initial bonding happens quite quickly, although I usually apply the PVA to both parts to be glued together.