Thread: Pin holes/bubbles in NC lacquer

Rod,

A trick PJT taught me for filling cracks/voids in veneers might be of use to you.

I use a flour sieve to produce a reasonably fine sawdust product. This sawdust is rubbed/pressed into the imperfection and the excess blown away. Then, a little super glue is dripped onto the sawdust. (Use only the original thin product, not the rubberised, thicker product.) A minute later it can be sanded off. It occurred to me that if you used very fine sawdust the same technique might work with the fine cracks in your jarrah, providing you can press the sawdust into the cracks.

Many thanks to PJT. I have used this approach to successfully fill cracks, voids, knotholes in both veneers and solid timber.

Originally Posted by John Samuel

Rod,

A trick PJT taught me for filling cracks/voids in veneers might be of use to you.

I use a flour sieve to produce a reasonably fine sawdust product. This sawdust is rubbed/pressed into the imperfection and the excess blown away. Then, a little super glue is dripped onto the sawdust. (Use only the original thin product, not the rubberised, thicker product.) A minute later it can be sanded off. It occurred to me that if you used very fine sawdust the same technique might work with the fine cracks in your jarrah, providing you can press the sawdust into the cracks.

Many thanks to PJT. I have used this approach to successfully fill cracks, voids, knotholes in both veneers and solid timber.

Thanks for that John. This is the bag of Jarrah dust (like talc) that has been collected in the dust extraction unit over a long period of time and I'm surprised that it is all Jarrah coloured as other timbers have been machined as well. My process has been to mix it in with the lacquer or apply the lacquer to the item and then sprinkle the dust on and work in. It works but is a long slow process as the lacquer can take time to dry.

My Solarez arrived this morning. Because there are several Solarez products, here is a pic of the one I bought (about $55-60 for a pint, including shipping). It is a combined sealer/filler, but is a clear product. I was expecting a white product (as per the video), but heaven knows what new developments have occurred.

Solarez Sealer-Filler.jpg

Some testing notes follow. The tests were conducted with a piece of the same NG Rosewood board that gave me no end of troubles with bubbles and pinholes in the most recent job, a jewellery box, and a piece of Surian cedar.


FIRST TEST PIECE. NG Rosewood. Does the product eliminate pinholes and bubbles in a finish where the grain telegraphs through?
1. Wood was sanded with 120 grit on an orbital sander.
2. One coat only of Solarez was used. I wanted to see how easily the product defeated pinholes and bubbles.
3. Sanding done with 120 grit orbital (instructions say use 400 grit, but that was far too slow). I sanded it back until the wood started to show through, hoping the Solarez remained in the pores, but was concerned that 120 grit might scratch a lot of it out.
4. A full coat of NC lacquer was applied. At first there was a little "twinkling" on the surface, suggesting tiny pinholes or similar. I ignored this, sprayed on another coat whilst the first was still wet and waited to see the result. It worked. I could see no pinholes or bubbles. As expected, the grain did telegraph through the lacquer, and it is likely that some tiny pinholes were present in the deeper pores, but I could not see them and bubbles were non-existent.
5. The wood retained its rich red/brown colour. It looked the same as if sanding sealer and lacquer only had been applied. No opaqueness and no colour change. I got the same bright rich colour that is one of the key reasons we use lacquer.


SECOND TEST PIECE. NG Rosewood. Filling the grain entirely.
1. Wood was sanded with 120 grit on an orbital sander.
2. Three coats of Solarez were applied, sanding with 240 grit between coats.
4. A full coat of NC lacquer was applied. At first there was a little "twinkling" on the surface, again suggesting tiny pinholes or similar. I ignored this, sprayed on another coat whilst the first was still tacky. Once dry, I could see I had not quite filled all the pores with Solarez and some tiny imperfections remained. My guess was that one or two coats of sanding sealer would finish it nicely ... or another coat of Solarez ... so I brushed on a coat of sanding sealer, sanded that smooth and reapplied lacquer. The blemishes all but disappeared.


THIRD TEST PIECE. Surian Cedar. Fill the grain entirely.
1. Three coats of Solarez were used, sanded with 240 grit between coats.
2. Sanding sealer was applied with a brush because the gun was full of lacquer and I did not feel like changing it over.
3. Sanded with 240 grit and sprayed with NC lacquer.
4. Surian is notorious for producing a wooly finish when planing or sanding and for it's open pores which regularly produce bubbles or pinholes, especially on horizontal surfaces. However, one coat of the Solarez eliminated the wooliness completely. The lacquer finish, although only two coats, was free of bubbles and pinholes. I reckon that after a few more coats of lacquer this piece could be hand rubbed to a mirror finish.


CONCLUSION
This product will be a permanent feature in my shop until something better comes along. It takes only 15-30 minutes to apply three coats depending on sanding time. To prevent pinholes and bubbles, only one coat is necessary, but the grain will not be completely filled.

These are limited tests ... not at all comprehensive ... but the results suggest that one or two coats of sanding sealer over the Solarez is a good idea when a hand rubbed, mirror finish is sought ... but that might be due to the inexperienced operator.


I started with the objective of eliminating pinholes and bubbles. It did that well on all my tests. When the grain is not filled, I reckon there were some tiny pinholes still present, but they could not be seen in the completed finish. So far as I am concerned, this means that for practical purposes, they are not there.


A bonus is that with three coats it will fill the grain completely or almost completely, depending on one's skill and the size of the pores in the wood. This is not a magic bullet. For instance, if one runs the squeegee along the grain it can scoop the product out of the pores a bit ... a little skill and care is required ... but not a lot. I still got a few tiny bubbles on one section, but that is only an issue when hand rubbing a mirror finish (for which a couple of coats of sanding sealer is indicated). Doubtless I have more to learn about this product. Nonetheless, it seems to have solved a problem that has irritated me for a very long time.


One positive characteristic is that this product is 100% solids, and so does not shrink during cure. This is why it is so great at filling the grain with repeated coats. Another is that you can take as long as you like smoothing out the finish. It will not cure until you put it in the sun. Finally, being able to spray finish coats a few minutes after applying the Solarez and sanding it smooth is a real boon.


The first coat wets the wood surface completely. One should use less product for the second and subsequent coats because the squeegee removes most of the product sitting on the surface, which is now sealed, leaving only a very thin smear and the product that is sitting in the pores. Use sparingly. Also, get the surface as smooth as possible before exposing it to the sun. Any ridges left by the edges of the squeegee will cure as ridges and must then be sanded smooth.


At about $55-60 for a pint it is not cheap. However, if i use it only on the tops of my cabinets, which is the plan because that's where I get the bubbles and pinholes, a pint will last a long time because it is used so sparingly. By my reckoning it is excellent value for money. It reduces the number of coats of sanding sealer required (or eliminates them) and the elimination of bubbles and pinholes saves a lot of time and frustration. Even if 5 or 6 coats are needed to eliminate the grain/pores when desirable, it is still far quicker and easier than all the other methods I have tried. Although it will solve my initial problem, pinholes and bubbles, it will be a handy product when I want a hand polished mirror finish, such as jewellery boxes.


If you are guessing that I like this product ... quite a bit ... you are correct. It is not perfect, but it is a vast improvement on all my earlier approaches. At the very least it is well worth buying a pint and running your own tests. If after using it on real furniture rather than test pieces I make any new discoveries, I'll post them here.

John,

Thanks for taking the time to write up your findings. Sounds like you’ve found a winner! I look forward to seeing some of your boxes finished using Solarez.

Regards,

Brian

Thanks for the info John.

So where you are saying "solarez" and then further on a "sanding sealer" are you still referring to solarez or two different products?

Rod,

"Sanding sealer" is different to Solarez. It is the product I normally spray before applying lacquer. It seals off the timber and sands easily to a smooth finish but requires many coats to fill open pores and fill the grain.

Solarez can be used without any lacquer at all, in fact some luthiers do that. They apply 3 or 4 coats of Solarez. The last coat is sanded with 400, 600, 800, 1200 1500 and perhaps even 3000 grit. It is then polished with a cutting polish or similar to give a high gloss finish. You can do the same thing with lacquer to give a hand rubbed mirror finish.

I seldom want such a finish. Most of my furniture will get a single coat of the Solarez to the horizontal surface (to avoid pinholes and bubbles), followed by two or three full coats of lacquer which is sanded flat with 400 grit. Finally I apply a thin, fast drying coat of lacquer. The top of the cabinet is then sanded with 1200 grit and polished (to get rid of dust specks and the insects that may have landed on the wet lacquer).

When I want to fill the grain completely I'll likely use three coats of the Solarez followed by 1-2 coats of sanding sealer followed by lacquer. I like lacquer because it is very easy to repair and because it never leaves a witness line during the repair process.

Originally Posted by homey

John,

Thanks for taking the time to write up your findings. Sounds like you’ve found a winner! I look forward to seeing some of your boxes finished using Solarez.

Regards,

Brian

Thanks, Brian.

I seldom produce mirror finishes these days. Most women don't like them, except on things like jewellery boxes and I only make one or two of those a year.

However, I have been tormented by pinholes and bubbles, especially in cabinet tops made from timber like NG Rosewood and cedar, for a very long time. It was a breakthrough when the Solarez stopped those issues in today's trials. We can apply a coat of Solarez to a cabinet top and sand it flat in ten to fifteen minutes, maximum. In the past I have lost days fixing pinholes and bubbles on some jobs. If today's trials are any indication we can proceed with lacquer confident that we will not suffer pinholes and bubbles. I have half a cube of NG rosewood sitting in the racks. Until today, it was mocking me ... threatening to curse me with pinholes and bubbles. After today's trials I had a brief chat with that timber and made sure it knew who the boss was from now on.

Sounds brilliant John. I have a couple of pieces of highly figured eucalypt with numerous natural defects (holes) and presume Solarez would be ideal for filling these.

Originally Posted by tony_A

Sounds brilliant John. I have a couple of pieces of highly figured eucalypt with numerous natural defects (holes) and presume Solarez would be ideal for filling these.

Tony,

I suspect that is a function of how big your holes are, but am sure you have several approaches to fill the larger holes. I think we need to bear in mind that if the sun's UV light can't reach the Solarez, it won't cure.

I have some Salmon gum timber. It has lots of gum veins and also drying some cracks as per photos 1 and 2. Today I decided to use the solarez grain filler with two applications and sanding with 150 grit (no clogging) the results being as per photos 3 and 4. I'm very impressed, the crack on the end of the board is almost filled apart from where the solarez leaked on the edge. Previously I'd been resin filling as per photo 5 but its messy and time consuming and sanding will clog.

Originally Posted by rod1949

I have some Salmon gum timber. It has lots of gum veins and also drying some cracks as per photos 1 and 2. Today I decided to use the solarez grain filler with two applications and sanding with 150 grit (no clogging) the results being as per photos 3 and 4. I'm very impressed, the crack on the end of the board is almost filled apart from where the solarez leaked on the edge. Previously I'd been resin filling as per photo 5 but its messy and time consuming and sanding will clog.

Great work, Rod. You have filled bigger defects than I have attempted.

Usually, I fill the bigger defects with sawdust and then apply super glue. After sanding (only a few minutes later, especially if I have dampened the sawdust a tad) I apply the Solarez.

Sometimes, I still use resin where big defects are encountered and where strength is mission critical for the repaired piece.

Nevertheless, until something better comes along, Solarez will have a home in my shed. It is a very handy product.

When you say “diluted”, I presume you mean thinned? With thinners?

Originally Posted by riverbuilder

When you say “diluted”, I presume you mean thinned? With thinners?

Mate,

I can't find the word "diluted" anywhere in this thread except for your post. Am I missing something?

I had the problem of "pinholes" coming up in the finish. After much deliberation, I asked a local panel beater to have a look at my set up. He said the problem was water vapor, because the water/oil trap was to close to the compressor, and did not allow the air to cool enough to release the vapor. I added a second trap with a metre of hose between the second trap and the trap at the compressor and have not had a problem since. I release the water from the traps as further security.

Jim