Lacquer cure time

[Gerald Lawrence]

I have begun to use some lacquer, mainly in Ringmaster bowls. Not having real good luck buffing with the Beal system. It seems to take some of the finish and cause it to ball up and takes a while to get this off. Seem to have better luck using white diamond only. What is the minimum cure time for lacquer? Am I right to avoid the red rouge for buffing?

 

[Jerry Bailey]

I too just started trying some glossy lacquer, have 2 bowls drying/curing
from everything I've read, cure time could be minimum 7-10 days
and definitely skip the Tripoli, start with White Diamond, then the Carnuba

would be interested in hearing your experiences with buffing and final appearance,
I might just sand mine to 1500-2000g & then use carnuba only just to smooth out surface.

 

[Mark Mandell]

Lacquer

Morning Gerald,

Lacquer, like shellac, is an evaporative finish composed of a resin dissolved in solvents. Lacquer doesn't "cure" like reactive finishes. Instead, as the solvents evaporate, the resin is left behind. The resin will not reach its full hardness until all of the solvents have evaporated. Depending on environmental conditions and how many coats have been applied, it can take anywhere from a week to a month or more before the evaporation process is complete. During that time the lacquer will be soft and your description of it "balling up" confirms that your coating has a way to go before it reaches its full hardness. Evaporative finishes have the great advantage of 100% burn-in, meaning that each successive coat partially redissolves the prior layer such that many coats of the lacquer actually form a single layer. This unique characteristic was used by Eastern artists to make carved lacquerware where a bowl or jar was made of many coats inside a form and then removed to be carved and polished. You must, however, allow all of the solvents to evaporate before going further. Keep in mind as well that as the solvents evaporate, the coating will thin out considerably. What started out as a 7-9 mil thick coating may only be 3 mils thick when fully dry and hard.

When buffing lacquer, you should also keep in mind that it will easily be effected by friction heat such that you can get burn marks in your coating. Machine buffing lacquer should be done with the finest abrasives and with very light contact between the surface and the buffing wheel to avoid heating the surface any more than necessary. Before you go to your buffer you should level the surface with abrasive paper to at least 1,000 grit or higher. Buffing an uneven surface will make it shiny, but will also amplify the surface defects like bumps or scratches.

 

[john lucas]

I switched from Deft lacquer to a local commercial lacquer. It dries hard enough to buff in a day. I also use 3" wheels at about 1500 rpm instead of the 8". It was simply too easy to burn through the lacquer with the 8" wheels. Much more surface feet at the same RPM with the 8" wheels vs the 3".

 

[Grant Wilkinson]

I buy pre-cat lacquer from a local commercial supplier. He has told me that the minimum safe time to buff with white diamond is a week. Even then, put no pressure on the wheel, as the heat generated will ruin the finish. So far, that has proved to be good advice.

 

[Mark Mandell]

Making Them Shiny

While it may seem anathema to dedicated machine-users, I point out that I can get the same results as power buffing with none of the risk by using rubbing compound and a bit of hand work. I have used Meguire's auto compounds to very good effect on both solvent and acrylic lacquers as well as on drying oil/resin finishes like Waterlox High Gloss. The key is a leveled finish film that has been properly refined. I use three or four grades of compound finishing up to a mirror surface with "swirl remover". I do not, however, wax my finishes after they've been rubbed out (polished) as I see no benefit in putting wax on an already-polished surface.

Granted, the machine buff is faster, but I'm never in that much of a hurry.

 

[Bill Boehme]

I have started using pre-cat lacquer on some of my turnings. It levels better than the regular fast drying rattle can stuff. I hand sand to level the surface and then continue with progressively finer grits up to 12,000 and then use high gloss polish with cotton balls for the final step. I don't use a buffing wheel, but if you must then first sand to level the surface. Otherwise, buffing only shines up the irregularities in the finish.

 

[Gerald Lawrence]

Thanks for the ideas and info. This will definitely be a learning process in progress.

 

[Jerry Bailey]

I've got 2 bowls, a red, and a blue .... each have roughly 15 light coats, allowed to "dry" 24 hours and lightly sanded between coats
then let set for 10 days before I started final finishing (was no smell, and read that evap/cure was done when you couldn't smell finish)

I've already tried once with the "red"
hand sanded from 800 thru 8000, got a nice smooth surface with none of the "balls" Gerald has gotten
wiped/blown clean, and then have tried 3M's Finesse It II (by hand, not using buffing system on lathe)
Had read Finesse It was same result as Mark's Meguire's compound, hence me using it as it was available locally ......
final finish was a good glossy look, but still cloudy looking (definitely not what I wanted)

I lightly dried sanded, should I have wet sanded instead?
When using the Finesse It, should it be applied and let dry before buffing?
I understood that applying and rubbing in small circles until gloss appeared, not letting compound dry, then do a light buffing
(directions weren't very complete)

(didn't start new thread as I figured info would also help Gerald)

 

[Mark Mandell]

I've got 2 bowls, a red, and a blue .... each have roughly 15 light coats, allowed to "dry" 24 hours and lightly sanded between coats
then let set for 10 days before I started final finishing (was no smell, and read that evap/cure was done when you couldn't smell finish)

I've already tried once with the "red"
hand sanded from 800 thru 8000, got a nice smooth surface with none of the "balls" Gerald has gotten
wiped/blown clean, and then have tried 3M's Finesse It II (by hand, not using buffing system on lathe)
Had read Finesse It was same result as Mark's Meguire's compound, hence me using it as it was available locally ......
final finish was a good glossy look, but still cloudy looking (definitely not what I wanted)

I lightly dried sanded, should I have wet sanded instead?
When using the Finesse It, should it be applied and let dry before buffing?
I understood that applying and rubbing in small circles until gloss appeared, not letting compound dry, then do a light buffing
(directions weren't very complete)

(didn't start new thread as I figured info would also help Gerald)

Hi, Jerry,

As with Meguire's, there are several grades of Finesse It, and, from what you describe, I suspect you haven't gotten their finest polish. You might try an auto-body "clearcoat" polish to remove that haze and get that deep gloss you're after.

BTW, when using solvent lacquer, you need not sand between applications unless you're removing a sag, drip, or dust-bugger. As explained above, a new application of solvent lacquer redissolves some of the previous coat so that, rather than just sticking to the surface (like an oil finish), the new application actually fuses with the older to form a single-layer coating.

 

[Jerry Bailey]

Thanks for the reply Mark

I use three or four grades of compound finishing up to a mirror surface with "swirl remover"

care to share which ones you use?

I got the only 3M Finesse It product available, since I have to order online, might as well get something others are familiar with to get proper answers
I checked Amazon and there are like 10 different compounds (Meguire's), don't mind spending the money, just want to buy the right stuff 1st time around 😉
Since this is technically an automotive product, hard to get reviews when working with woods.......

had tried the Finesse It because there was a brief article on Wood central, but again, instructions were very vague.......

As for the sanding between coats, I'm aware, just used to the furniture industry and is an old habit, get a smoother flatter coat when applying to smoother flat surface
When you sand for final finishing, do you dry sand or wet sand? and does the wet sanding and "slurry" make that much of a difference in the finish?

TIA

 

[Mark Mandell]

Thanks for the reply Mark

care to share which ones you use?

I got the only 3M Finesse It product available, since I have to order online, might as well get something others are familiar with to get proper answers
I checked Amazon and there are like 10 different compounds (Meguire's), don't mind spending the money, just want to buy the right stuff 1st time around 😉
Since this is technically an automotive product, hard to get reviews when working with woods.......

had tried the Finesse It because there was a brief article on Wood central, but again, instructions were very vague.......

As for the sanding between coats, I'm aware, just used to the furniture industry and is an old habit, get a smoother flatter coat when applying to smoother flat surface
When you sand for final finishing, do you dry sand or wet sand? and does the wet sanding and "slurry" make that much of a difference in the finish?

TIA

Meguire's : I usually started with No. 2 or 3 Fine Cut, then No. 5 Machine Glaze, then No. 9 Swirl Remover, and last (same brand) Polishing Compound.

I have also used Menzerna products on flatwork starting with their No. 2L Pre-Polish, then No. 16 Fine, and finally their "Final Polish".

On solvent finishes I only dry sand because they powder off so nicely when fully dry and don't clog the paper. Wet sanding can assist to make your SiC paper last longer, but you need to be picky about completely removing the slurry. Obviously when you refer to "wet" you're talking water right? It won't help a lacquer finish like it will on a oil varnish, because the remaining sediment will "lift" into the wet coating and interfere with clarity, visual depth and light refraction in the coating. You'll also have to make sure that your surface is bone dry with all water removed lest you trap water under the new wet coat and get blushing.

You might care to contact Don Derry about finishes. http://www.donaldderry.com/2index.html He produces truly exceptional finishes and may share what he uses in the way of compounds.

 

[Jerry Bailey]

Thanks again for the reply Mark
tried link, domain couldn't be found, but saw some images from Google, saw an awesome open vessel yellow/blue with an eye painted, loved it!!
will try link again later as I'm curious to rest of his works, thanks for that too

as for wet sanding, yessir, meaning using water, never wet sanded before and glad to hear you're not, but have been seeing it a lot lately in my readings.
prefer dry sanding as I can "feel" any discrepancies in wood better than I can see them.
Also thanks for the details on the polishing compounds, going to Amazon to order, good to know the right ones to get in advance, hate wasting monies trying things

usually use/do food safe finishes (oils/wax) and satins/matte, but some people wanting glossy, have to give them what they want even if I personally don't like it 😉
so trying different ones, like the lacquer, also have a 10" Sycamore bowl on lathe where I'm testing using Waterlox (don't like how it darkens wood, but like it's finish)

again, thanks for all info .......... off to Amazon to order the Meguire's I need ......

Gerald, will also be waiting to read how you fare, and your experiences 🙂

 

[Bill Boehme]

Jerry, concerning your earlier post about sanding after every coat of lacquer, that sounds excessive and potentially contributing to less than perfect results. Before the first coat is applied, all surface problems must be dealt with because the finish isn't going to fix anything. Each coat of lacquer, if applied correctly, is very thin once dry. Sanding can easily cut through it. Each coat partially dissolves the coats already applied so sanding that is needed for varnishes, isn't needed for lacquer. The more time that you spend sanding, the more uneven the surface will become. Fifteen coats seems excessive, but you may have sanded away half of them. Most of the time, three coats seems to be sufficient for me. If it isn't there must have been something wrong with the surface prep.

Concerning the haze that you see after polishing, it could be caused by several things. Something that took me a while to figure out is that the polishing cloth was the culprit while I was blaming the polish. Without really thinking, I was using paper towels ... not much better than 800 grit sandpaper. I don't remember where I saw it, but jumbo cotton balls solved the problem. Use little circular motions with plenty of polish and keep changing to fresh cotton balls or else you are just rubbing lacquer swarf around. Don't do any of this with the lathe running. I haven't been impressed yet by any of the power buffing that I have seen. I can understand why so many turners speak with disdain about high gloss finishes because most of what I have seen isn't done well. It just draws attention to what shouldn't be seen -- bumps, ripples, sanding lines, discontinuous curves, and whatnot. Finally, I only use high gloss where it "fits".

 

[Jerry Bailey]

Thanks for the reply Bill
Looks like I have 30+ years of "habit" to unlearn comparing furniture/cabinets & lathe working 😉

Only thing it seems I have done correctly so far is my prep sanding, I guarantee piece is flawless before applying any of my finishes.
The sanding between coats was just habit, and turning inexperience, but as you said, I probably sanded 1/2 away each coat.
The excessive amounts of coats was again just me, thinking the thicker the finish, the least likely I'd go thru when sanding for polishing/buffing.
again, turning inexperience 🙁

When I buffed with Finesse It, I used old cotton t-shirt, but cotton balls made sense to me when I read your initial post, and was going to try that next go-round.

Another reason/example of why I joined this forum ....... I have a lot to "unlearn" and a bunch of habits to break LOL 🙄

 

[Gerald Lawrence]

Thanks again for the reply Mark
tried link, domain couldn't be found, but saw some images from Google, saw an awesome open vessel yellow/blue with an eye painted, loved it!!
will try link again later as I'm curious to rest of his works, thanks for that too

as for wet sanding, yessir, meaning using water, never wet sanded before and glad to hear you're not, but have been seeing it a lot lately in my readings.
prefer dry sanding as I can "feel" any discrepancies in wood better than I can see them.
Also thanks for the details on the polishing compounds, going to Amazon to order, good to know the right ones to get in advance, hate wasting monies trying things

usually use/do food safe finishes (oils/wax) and satins/matte, but some people wanting glossy, have to give them what they want even if I personally don't like it 😉
so trying different ones, like the lacquer, also have a 10" Sycamore bowl on lathe where I'm testing using Waterlox (don't like how it darkens wood, but like it's finish)

again, thanks for all info .......... off to Amazon to order the Meguire's I need ......

Gerald, will also be waiting to read how you fare, and your experiences 🙂

Jerry, I have not been happy with oil on sycamore. This time I sealed with blonde shellac and put on first 2 coats of General Finishes Woodturners finish. Looks good right with very little or no darkening. Will post something on shellac when done. Was high humidity yesterday and I forgot and sprayed. It did cloud, but cleared today.

 

[Jerry Bailey]

Thanks for the reply Gerald
This is my 1st piece of Sycamore, not sure what made me decide to test the Waterlox with it , but ..
I did do an initial seal with 3 coats shellac/dna mixture I learned from Jimmy Clewes
Should've realized the Waterlox would darken as it's almost as black as my morning coffee, but I do like the finish it leaves. 😀
Haven't tried the General Finishes so will be interested in your results