How do I know there is enough polyurethane coats?

Beyond the Manual
1

I been experimenting with unfinished softwood plywood (I think its pine). And I have to be careful and not use a scraper or gorilla tape as it takes off bits off wood :sleepy:. After scoring and cutting, I hand remove the mask. To protect it, I tried Watco wipe on polyurethane which I makes the color more golden colour but I canā€™t tell how many coats is enough that the wood is protected. Iā€™m making wood brooches so needs to be enough for gentle daily wear. Instructions say to coat it 2 or 3 times but it seems to soak into the veneer and doesnt seem ā€œfinishedā€. How do you know itā€™s enough?

2

Wipe-on finishes are generally more of a matte finish. Generally you will want to apply per the directions. When the finish stops being absorbed, that is generally as much as the wood will want to take.

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Instructions say 3 coats, doing 4 or 5 would be normal? I guess I dont know what point by looking at it if it taking more and need more experience to just ā€˜knowā€™

4

As mentioned, the wood will stop absorbing finish. So you can do three and then see if you still get some spots that are not finished. If so you can add another coat. Just start trying it.

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5

Iā€™m a minimalist. One light coat and done if I had good coverage.

Maybe two if itā€™s like a handle for a sword or something.

But donā€™t listen to me :slight_smile:

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6

I ran into the same situation.

I was applying to much polyurethane. I was trying different methods of applying it too. At first I would just ā€œwetā€ the surface; let it dry and repeat (I think this is the proper method?) Later, I was almost pouring it on, and letting it ā€œcureā€ almost like epoxy (this was far to much).

I found I had the best result with just brushing it on, let it dry, and look to see if there were any spots that were ā€œnot finishedā€ (looking for that slight reflection of light). Repeat until it looks like what you are going for.

I am no expert, this is just want I have learned from trial and errorā€¦

I also noticed the slight change of the color, and I found that this was the polyurethane picking up and mixing with the burned residue. I almost looks like stain, but I found that if I cleaned the wood first, that ā€œcolorā€ did not happen as much.

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7

I do a minimum of 3 coats, wiping it on with a rag. Between coats, I sand lightly with 600 grit sandpaper. If it feels smooth after sanding, I apply one more coat and call it done. How many coats depends on the wood. Three coats are usually enough for maple, cherry, walnut, mahogany, and birch. Poplar takes 4 to 5 coats. Pine and fir can require even more. I do not use wipe on polyurethane for open grain hardwoods like oak. Those need a paste wood filler followed by 3 coats of brush on polyurethane or polyacrilyc to get a really smooth surface.

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