Use of Lacquer/Thinner on punky wood

Re: Use of Lacquer/Thinner on  punky wood

john lucas

I use lacquer thinner with lacquer and mix it about 50/50. You want it to penetrate. After a few coats have sunk in you can mix it a little thicker, maybe 30 percent lacquer thinner. You want it to penetrate and harden the fibers.

For punky wood the first thing to try is to simply wet it then use a gouge with the most acute cutting edge and try your very best to not push the cut, let the gouge do the cutting. I use the Hunter Hercules or Hunter #5 because the cutting tip is about 30 degrees which is more acute than most other tools you use.

Sometimes if it's not extremely soft wood you can simply apply a thick coat of paste wax and then use the Hunter tool and it will cut clean.

Dealing with punky wood is a challenge. You need to do whatever you can to harden the fibers. The use the sharpest tool that will make the cut, then increase the speed of the wood and decrease the amount of forward pressure on the cut. Try to make the cutting angle of the tool so it's a shear cut, and take very small cuts.

Re: Use of Lacquer/Thinner on  punky wood

John K Jordan

I'm no expert but this is the way I do it: with either lacquer sander sealer or shellac-based sanding sealer. I think I read that sander sealer is about the same as the undiluted finish thinned with the appropriate thinner.

I put sealer all over the piece, usually with a brush. I keep applying more to soft areas until appears to be saturated. Let dry, possibly overnight, then repeat. Turn a bit then apply more at the first sign of new soft areas exposed.

I may have mentioned this elsewhere, but if it is really soft and punky, I prefer thin CA glue. I also apply it all over the surface to prevent the CA areas from looking different and hard boundaries, however I sometimes wipe the CA from the soft into the normal wood with the grain or figure to mask the boundary. This works better in some cases than others. I also soak the punky areas with more and more CA until they stop accepting the glue. Good ventilation is required. Turn away some wood and repeat as unsaturated areas can be exposed.

With the CA method I have salvaged wood that was impossible to cut without major tearout or so punky it was crumbly. The CA is sort of a quick stabilization infusion. There has to be some very good reason to do this rather than throw it in the burn barrel.

JKJ

Re: Use of Lacquer/Thinner on  punky wood *LINK*

Doc Green

I've worked a lot of punky wood because I keep the good stuff for firewood - it has a great BTU content and will last longer in the stove.

I use lacquer sanding sealer as described in the articles linked below.

If you soak the piece in a pot, it will take FOREVER to dry. And you must let the sealer dry to "a prickly feel" for this method to be effective.

Good Luck!


http://www.docgreenwoodturner.com/spalted1.html

I have long used lacquer.......

JamieDonaldson

.....and about a 10% mix of acetone for sanding sealer/spalted wood hardener and sometimes a final finish rubbed into the wood.

is there a reason you use Acetone vs lacquer thinn

John, I'm not sure exactly what ....

JamieDonaldson

....lacquer thinner is, maybe MEK but there are several formulations, and I'm not at home just now to check. I'm spending most of the weekend in the hospital with my younger brother who crashed his small plane yesterday, and right now is in surgery. I have always had acetone in stock for numerous other applications such as bonding plastics, epoxy solvent, so I use it. It seems to penetrate deeper and dry more quickly in my lacquer mix.

Re: John, I'm not sure exactly what ....

john lucas

Thanks Jamie. I use lacquer thinner simply because it's the same company that makes my lacquer and I fee like it should work better. It's also my finish of choice for lots of work so I can just mix in more finish or more thinner depending on what I need that day.

Please elabaroate...

Hal Taylor

John, can you elaborate a bit on your decision making in amounts of lacquer to thinner.

Re: Please elabaroate...

john lucas

Sorry to just throw that out. I mix lacquer and thinner together to get the viscosity I want that particular use. For example I mix it thin, about 50/50 for use in my spray gun for thin coats or to wipe on punky areas with a brush to get it to penetrate deeply. I mix it less thin, about 30 percent thinner when I want to spray on thicker coats or need it to build in the punky areas, not just penetrate. I haven't used it full strength ever I don't think. This is a commercial brand of lacquer that I buy locally but I used to do Deft the same way. I have to play with the viscosity when I spray because I spray outside and in Tennessee the humidity affects how it sprays quite noticeably. I often add a little retarder to make is spray better without orange peel. Can be quite challenging to use sometimes but I really like it for my hand mirrors so I keep using it, although right now my compressor is down so I have been using minwix wipe on poly and reserve the lacquer for wipe on applications or for strenghtneing punky areas.

Like some have said thin CA works really well except for 2 things. One is it's expensive. I hate to use up a $5 bottle trying to save a bowl that may only sell for $35. Lacquer is much less expensive. CA will also often stain areas outside the punky area. This can look quite bad. The lacquer will also discolor areas outside the punky area but if you use lacquer for the finish it blends right in. Lacquer isn't as bad about penetrating areas outside the punky area if it's side grain so it dissappears with a few light passes of the gouge.

cost of CA

John K Jordan

>>>CA works really well except for 2 things. One is it's expensive. I hate to use up a $5 bottle trying to save a bowl that may only sell for $35.

Ah, that's the problem! If you give everything away instead of sell it an extra $5 or $10 doesn't matter. Of course, I never studied business or economics.

JKJ

Drying time

Dick Coers

Lacquer thinner is formulated with different solvents to give the lacquer a slower setting time. If you go to an automotive paint supplier, they will ask what drying speed do you want. In the summer you need much slower drying so moisture is not trapped in the finish causing a blush. Acetone is basically an instant dry solvent.

Aqueous poly urethane products as alternative

Mike Brazeau

There are aqueous urethane based products available. I have used PC petrifier on some spalted maple for a wig stand. https://www.pcepoxy.com/products/wood-repair/pc-petrifier/

Want to try it on a bigger scale but have not got around to it. In US it is listed by HD and up to gallon quantities. Avoids the noxous odors and safety issues of lacquer thinners and acetone.

Re: Use of Lacquer/Thinner on  punky wood

Mike Stafford

I like to use lacquer sanding sealer to help consolidate punky wood. I mix the sanding sealer with the thinner that the company recommends and flood it on with a brush. I basically use a 50/50 ratio but I don't measure it exactly. I mix up small amounts at a time as it doesn't seem to keep well. Be sure to mix it up in a glass jar with a metal lid.

By the way I use Qualalacq brand sanding sealer and proprietary thinner. It seems to have a high solids content and dries very rapidly, particularly in this weather.

Re: Use of Lacquer/Thinner on  punky wood

Ron Bauer

If it's so bad you have to go through all these gyrations maybe you should throw it in the scrap pile. Like is too short to turn bad wood. This of course is IMHO.

Re: cost of CA

Jimmy Edwards

John, I buy all my CA glue from EZbond.com. Example: 16 oz for $16.90. There is a minimum order, so our club, when ready, get together and reach that minimum. They have all the sizes and accessories.