Help with patchy finish from water-based varnish

8 years ago

Hello All,

We're in the middle of refurbishing a mahogany sideboard, and we're using a water-based varnish to finish it. After 2 coats of varnish (currently waiting for the third to dry), the piece is looking patchy and a couple of stains have appeared out of nowhere (on ink, the other might be oil). Any suggestions on how to fix it?? Here are the steps we took:

1. Sanded it down to bare wood (finished with 240 grit sandpaper)

2. Vacuumed up dust, then wiped down with a damp rag

3. Put down first layer of varnish and let dry 24 hrs

4. Sanded piece with 240 grit sandpaper then wiped down with damp cloth

5. Put down second layer of varnish - still patchy

6. Repeated steps 4-5 - still patchy!

Thanks in advance for your help!

/Nomusa

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Comments (3)

Kaillean (zone 8, Vancouver)
8 years ago
last modified: 8 years ago
Is that teak? Teak can be tricky because it has a lot of natural oils. So the finish of the wood is likely absorbing the water base varnish differently in spots. Teak is often left unvarnished for this very reason. If you’re determined to varnish, you will need to use an oil based product for best results. Start with an extra thin layer to prep surface. Spar or marine varnish works best on teak.

You will have to sand off the water based product.

Oil is another option and looks great.
nomsinomsa thanked Kaillean (zone 8, Vancouver)
nomsinomsa
Original Author
8 years ago
It's Mahogany (or Tola - not sure which coz my research showed the piece was made with either or). I assume I have to stand it down to bare wood again before using an oil-based varnish, right?
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Kaillean (zone 8, Vancouver)
8 years ago
I’d say 95% this is teak and not mahogany. Mahogany has a different grain and is not nearly as oily as teak. Usually takes a finish well.

You can use mineral spirits on a rag to remove a lot of the finish and then sand down. An oil based product will give you a better finish anyway and be less tacky to the touch.
nomsinomsa thanked Kaillean (zone 8, Vancouver)