Paulownia Precision

Couldn't resist seeing it would look with the pickguard and bridge.

Attachment 39030

Next planned step, after letting it rest a good long while, will be to add AquaCoat grain filler.

Once the pore filler is in place, I'll make a decision about pre-drilling at least for the bridge and the neck.

Would welcome advice. I know that the board is a bit split on pre-drilling. I have always drilled after the finish is on, but there were a couple of close calls on the last build that have me thinking about pre-drilling. Still debating with myself on that. Paulownia is pretty soft, and it's easy to mark inadvertently. Finish might actually make it easier to handle without damaging when I get to that phase.

At the moment I am thinking I will pore-fill first, then decide about pre-drilling at least the holes for the bridge. Would welcome the wisdom of folks who have worked with pine or paulownia or kiri or any other soft wood.

Also, for those who pre drill... Do you pre drill and mount the neck too? On all my builds so far, I have had the neck bolted in place before drilling for the bridge. It's been one of the reasons for not drilling until the finish is on. Do folks who pre-drill actually mount the neck first?

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Also, for those who pre drill... Do you pre drill and mount the neck too? On all my builds so far, I have had the neck bolted in place before drilling for the bridge. It's been one of the reasons for not drilling until the finish is on. Do folks who pre-drill actually mount the neck first?

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I'm a "pre-driller" and I drill before any finish (stain/dye/paint) is applied at all. The neck has to be in place in order to lay out the correct placement, but I just mark the hole positions for bridge, pickguard etc and drill without the neck in place.

The second thing I do is slightly bevel the top of the holes (countersink). This minimises how the paint or clear coat builds around the opening, so when the screws are turned in, it minimises the risk of the paint/clear lifting from the action of the screws "pulling" at the finish.

The critical step I take is before wet sanding the paint/clear, is fill the holes with bee's wax. The wax prevents water going down the holes that can cause swelling around the holes. Any excess wax that may smear will wipe off with a bit naptha on a rag. Also the wax acts as a lubricant for the screws.

As for grain filling after staining, I would have intuitively advised against it, but looking at the Aquacoat website, it says it can be done pre or post. If I were using it, I likely would do it pre-stain, but I guess I'm old fashioned that way :o.

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Originally Posted by McCreed

I'm a "pre-driller" and I drill before any finish (stain/dye/paint) is applied at all. The neck has to be in place in order to lay out the correct placement, but I just mark the hole positions for bridge, pickguard etc and drill without the neck in place.

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But you do pre drill the neck and mount it to mark the bridge position? Or do you just clamp it in place for marking the bridge location and drill the neck holes after finishing?

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The second thing I do is slightly bevel the top of the holes (countersink). This minimises how the paint or clear coat builds around the opening, so when the screws are turned in, it minimises the risk of the paint/clear lifting from the action of the screws "pulling" at the finish.

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I had completely forgotten about your countersinking trick.

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The critical step I take is before wet sanding the paint/clear, is fill the holes with bee's wax. The wax prevents water going down the holes that can cause swelling around the holes. Any excess wax that may smear will wipe off with a bit naptha on a rag. Also the wax acts as a lubricant for the screws.

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Do you do anything to make sure the bees wax does not prevent the finish around the hole from adhering? That's the one thing that makes me leery of using wax in the holes.

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As for grain filling after staining, I would have intuitively advised against it, but looking at the Aquacoat website, it says it can be done pre or post. If I were using it, I likely would do it pre-stain, but I guess I'm old fashioned that way :o.

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Thanks for chiming in. I remember your having written some of this, but nice to have it all in one place.

One benefit of having three TKD black belts in the family is lots of broken paulownia boards to experiment with. I read the same thing on the AquaCoat website, and tried it both ways. It worked pretty well over the stain. The AquaCoat went from transparent to red, but when I worked it in, it looked good, and the color pull was not very noticeable. Dye stain over the AquaCoat was a miserable failure. It really did not pernitrate at all. It might work with gel stains or non-dye type stains, though.

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But you do pre drill the neck and mount it to mark the bridge position? Or do you just clamp it in place for marking the bridge location and drill the neck holes after finishing?

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Are you talking about the neck holes in the body, or the heel of the neck?
If the heel, I have done it both ways. It's much of a muchness, but depending on your bench space available, it may be easier if it's fixed with screws.

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Do you do anything to make sure the bees wax does not prevent the finish around the hole from adhering? That's the one thing that makes me leery of using wax in the holes.

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I only use the bee's wax AFTER the finish is on and BEFORE wet sanding. I would never apply the wax to raw timber.

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Dye stain over the AquaCoat was a miserable failure. It really did not pernitrate at all.

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That's disappointing to hear. I have not tried the stuff due it's price here in AUS, but maybe being a water based product it gets to deep into the timber causing it to repel the stain. I presume you sanded enough that the "between the grain" areas were bare?

I think I sanded it enough, but I don't really have a standard for comparison. I know AquaCoat is super expensive in AUS...though much cheaper here than there, it's the most expensive grain filler I have found in the US as well. I am guessing it would work well with gel stain over it, or conventional wood stain, but if you are using a dye stain I suspect it could be a very expensive experiment that might fail.

All the finish products I use are water based. I have worried about it swelling the holes. The dye stain is particularly thin. The top coat is more viscous...so much so that it would fill in small holes and I would need a ream or drill bit to clean out larger ones, even if it did not swell from the water. In big holes I have used balls of masking tape which has worked OK. Is this something I should worry about with waterbased top coat, or is it viscous enough not to cause a problem with pre-drilled holes?

Ironically, the only non-water product I apply is when wet sanding. I learned the hard way not to use water to wet sand water based top coat--even after it has cured for four weeks. So for that I use mineral spirits.

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All the finish products I use are water based. I have worried about it swelling the holes. The dye stain is particularly thin.

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I have used both water based and alcohol based dye with pre-drilled holes and have not found it a problem. That said, I don't apply the dye so heavily that it pools or runs. The cloth is wet, but not dripping wet (IYKWIM). I suppose if it was applied so heavily it was running across the surface, there would be potential for it to fill holes and possibly swell, but that would be a very haphazard approach IMO and inviting a number of things to go wrong.

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Is this something I should worry about with waterbased top coat, or is it viscous enough not to cause a problem with pre-drilled holes?

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Unfortunately I haven't used any water based topcoat, so I can't say. All of my finishes have been sprayed lacquer, poly or hand-applied poly/Tru-Oil.

At this stage the stain is already on. I may go the split the difference route, and do the do the holes for the bridge, but leave the holes for the pickguard until the end. I have plenty of curing time to think about it. Thanks for going through the details!

Well, McCreed, you inspired me to do more reading and youtube viewing...and as usual that confused me.

The makers of my stain (General Finishes) suggested adding 10% of their topcoat. They say that this will "lock in the color to reduce color pull when you apply the first clear coat."

Meanwhile the makers of Aqua Coat say that when using a water based dye stain it's best to seal with dewaxed shellac or one of their sealers before using their grain filler. I figured I'd try it both ways to see what works best, and so am prepping some test pieces.

Attachment 39097

My kids are no longer breaking boards in TKD, but I have a few paulownia boards left from when they did. My earlier tests produced decent results without a seal coat, but it should be interesting to see the comparison. Reports to follow...

I have a little 1lb blond shellac from experiments on some maple scraps to see what it would do to the color of a maple neck. Other than that I have never really used it. Hoping it's forgiving. Also hoping it won't yellow the stain.

I'll be interested in your results. If for nothing else than my own edification.

I would expect at least a little bit of lift even with the shellac, but it shouldn't be drastic and is completely manageable with careful application. This is what I've experienced with both hand-applied poly and Tru Oil over both water based and alcohol based dyes.
It generally has stopped lifting (98%) after the 2nd coat has dried.

I should say that by "lift" (colour pull) it has not been a total smearing or smudging of the base colour, but a noticeable transference of colour to the rag I'm applying the top coat with. It's important to get nice even coats and not allow winrows to be left behind. This will result in a streaky appearance.

Again, interested in what your experience is.

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Originally Posted by fender3x

At this stage the stain is already on. I may go the split the difference route, and do the do the holes for the bridge, but leave the holes for the pickguard until the end. I have plenty of curing time to think about it. Thanks for going through the details!

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Paulownia is such a soft timber, I wonder if it would be worth while drilling and gluing in dowels where the screws have to go so they don't strip out when screwing into the Paulownia?