mdf paint

[joshuajoshua]

Hi!

I plan to give a layer of paint in the MDF material (for open baffle system).

Can anyone give me a suggestion, what kind of paint should I use? any wood paint?or....?

I don't have any experience building a speaker..

Thanks,

Joshua

[idaho]

automotive primer-theres some cheap spray cans at walmart

apply,
apply again
and then sand a little bit just to make it smooth but not too much as not to remove the primer.
MDF soaks paint like crazy if you dont prime it.

then pick a spray can color you want and then spray as many coats as desired/needed, wet sand as desired to obtain the smoothness you want starting with 400 grit then progress up to 800-2000 grit if you desire the smoothness. Be carefull not to over do it that you get into the primer or wood itself. Buff with a automotive buffer compound. That is the GENERAL way I do it.

Research, experiment, learn, it DIY.

[John L]

Shouldn't you use a sealer first?

[richie00boy]

Don't use automotive primer first as you will use gallons of it, MDF is like a sponge. Use a proper MDF sealer. Then you can use automotive primer and topcoat as normal. In the UK I use Rustins or Blackfriar. Bonda over your way do something suitable.

[AndrewT]

Hi,
I have found the flat (pressed) surface of the MDF board to be quite resistant to taking a paint coat. This seems to be much worse when using water based paints. The problem seems to be a lack of evenness combined with poor adhesion.

The edges are completely different. Repeated sealing and sanding to remove the irregularities and fill the gaps until the surface becomes as smooth as the pressed surface. I found this takes at least 4coats of sealer and undercoat before trying a couple of gloss coats (for window sills).

[pinkmouse]

Surely not a repeat of all this again?

There are some very good threads on this topic already.

[John L]

Originally posted by pinkmouse
Surely not a repeat of all this again?

There are some very good threads on this topic already.

Perhaps you can provide some links to the previous threads? I have been gone for quite a while myself, and am not up to speed on much that has already been written.

Another thought. Since there are threads that are stickey, and kept for posterity, perhaps we can also have one that goes over the art of finishing/painting/sealing?

[John L]

I have mentioned this many times on several other forums, and perhaps a few here of late. There is only one REALLY good all around sealer, that goes well with practically any porus surface, and as an added bonus works as a supurb finish as well.

I am talking about "Shellac". All you need do is purchase a pound of flakes from an internet source, and go to your local Lowes/Home Depot/Ace, and get a gallon of denatured alcohol. Create between a one to two pound cut, make sure it is well dissolved, and then you can brush, use a loaded clothe, or even use a refillable spray can and spray it on. Just let it dry, which is quick, lightly sand the surface with 0000# steel wool, and you are ready to finish. It's that easy, and you simply Cannot screw it up, guaranteed!

Then place your mixed 'cut' of shellac in the refrigerator, to keep it in good shape, and bring it out when you need it.

There are simply too many wonderful things to say about shellac, that it is by far the very best sealer AND finisher on the market. Only if you are going to get alcohol or water on it's surface for an extended time, or put the finish on fire, will it let you down.

You can get shellac from right here. I use "orange" and "blonde", but there are others. The Orange makes a great stain too, and saturates just like a dye stain, so coverage is uniform, not like the pigmented stains that are about all you can find at the hardware stores. So with something like orange shellac, you will stain AND seal at the same time.

Saves time. And just about anything will go over shellac, unlike other applications.

[pinkmouse]

Here's a couple that I remembered, searching will find others.

A solution to MDF expansion on joints, translams etc.

A 'how to' for High Gloss Finishing

[joshuajoshua]

Thank you all!!

Now I have a better grip to start the project...

Thanks,

Joshua