Repairing water damaged MDF cabinets

[publicIdaho]

On a cart and ready to hit the finish room. First a visit with the new Davids

[publicIdaho]

I put a coat of clear catalyzed vinyl sealer on first - have lots of that on hand and a limited amount of black tinted sealer.

I used the random orbit sander and paint thinner to quickly sand up the flats of the speakers, hand sanded the round edges.

Then it was time for a coat of black sealer. This shows off the imperfections much, much better than the clear coat.

If you find and little gaps that were missed with the epoxy, you can re-fill them. I used regular wood filler and it worked fine - DO NOT WET SAND WOOD PUTTY!

[publicIdaho]

At this point, it is time to move to finer paper and hand sanding. Wet sand with paint thinner - keeps the paper from clogging up. You need to have decent paper or the thinner will make it fall apart.

I used a nice little sanding sponge - one that has abrasive around 4 sides. These are pretty stiff and are great for the flats, especially where you are trying to blend in the edges. When the abrasive wore out, I wrapped some regular paper around the sponge and it worked great.

I also used a sponge with abrasive on one side that bends easily on the round edges. Also used regular paper here as well.

Wipe your sandpaper off with paper towels - it will keep the sandpaper going much longer.

[publicIdaho]

When wet sanding, you should be creating a nice slurry of removed finish and paint thinner.

Wipe it all off as best you can before spraying the next coat.

It is basically sand and spray at this point until you are happy with the smoothness of your cabinet.

[publicIdaho]

Lots of sanding and more coats added.

As new coats were added, I used finer sand paper 180 to 220 to 320.

Make sure when looking at your speakers while sanding to get the lighting behind the speakers. Get that lighting coming from well behind your work, not overhead. And move your head around as well as the speakers to get different angles to the light - it is very easy to miss things in the finish.

I saw a little seam showing through on an edge and gave it a couple extra shots with the gun. A little too much as it turned out.

[publicIdaho]

Sags are not the end of the world though.

Here is a shot of the seam.

[publicIdaho]

Same thing different angle, the bad stuff goes away. Can't see either the sag or the dent.

[publicIdaho]

Here is what the sag looks like after wet sanding for a little bit.

It is critical to let the lacquer set up good and hard - rushing this step when the lacquer is still a little soft will end badly.

[publicIdaho]

Sanding on the dent meant was a little harder - it always is much harder to sand out something that is low to the surface than something that is proud.

[publicIdaho]

Ready to spray again. I use a pressure pot that is big enough to put a gallon can inside - makes cleanup much easier.

On the inlet to the pot I have a water trap pressure regulator.

This is a pretty easy rig to use and not that expensive.

[publicIdaho]

After sanding and spraying, sanding and spraying, being careful to make sure that the edges where the cabinets had been taken down to the bare wood blended in smoothly with the existing finish, I was happy with the results and wrapped up the cabinets in blankets to take them home.

I let them sit a day and a half before wrapping them up - the lacquer will be dry to the touch fairly quickly, even when it is 40°F where they are being sprayed, but the finish takes much longer to harden up.

Two or three days after bringing them home, they were still stinking up the room, outgassing the last of the volatiles.

[publicIdaho]

All that was left was to get my assistant to help me put the drivers back in!

Pretty happy overall with the fix as done.

[Bas Gooiker]

Nice and detailed again... usefull tips and tricks for all of us.

[publicIdaho]

I was a teacher at one point in my journey through life and I always did like to try to impart a little wisdom, even though I was not very good at it. But I have been trained answer questions, so feel free to ask away on anything and I will try to help if I can.

[LelandCrooks]

Nice.