What is a French Polish technique on a lathe?

[Brian Kent]

I have tried a whole lot of finishes on lathe work. But I am not sure what it would mean to do a French Polish on a lathe. Could someone point me to a process or describe the materials?

Thanks

[Steve Schlumpf]

Brian, the term French Polish loosely means applying multiple thin coats of finish in order to achieve a high gloss. The key to success is to use very thin coats and allow to dry before applying more. By being very thin, drying time is greatly reduced and depending on temperature and humidity, you can often get multiple coats applied in a days time. I do this (off lathe) on all my WOP finishes.

[Brian Kent]

Well then I do that with several kinds of wipe-on finishes. Dewaxed shellac, WTF, WOP, leveled when needed.

[Doug Herzberg]

Brian, my understanding is that French polish refers to a blend of 1/3 shellac, 1/3 BLO, and 1/3 DNA. It is applied on the lathe with a cloth in several thin layers. The idea is that the BLO acts as a lubricant, allowing you to bring the shellac to a high polish before it gets too sticky. Some turners use the method because it allows them to finish a project quickly while on the lathe and move on to the next job.

[Brian Kent]

Good, Doug. I'll try that combination.

[Frank Drew]

In most traditional versions of the French polish method, the oil is only used as a lubricant to the pad which is actually apply the shellac finish. The pad is usually balled up cotton or wool wrapped inside a piece of fine-weave linen, or sometimes cotton.

[Allan Speers]

Brian, my understanding is that French polish refers to a blend of 1/3 shellac, 1/3 BLO, and 1/3 DNA. It is applied on the lathe with a cloth in several thin layers. The idea is that the BLO acts as a lubricant, allowing you to bring the shellac to a high polish before it gets too sticky. Some turners use the method because it allows them to finish a project quickly while on the lathe and move on to the next job.

Technically, french polish is a technique, not a formula. The really important part of the process is using a lubricant, like mineral oil, and an abrasive material like pumice, which sort of "sands" the top layer of the wood and creates a slurry that fills the pores. You can do it without the pumice, but then it takes much longer.

However, some species with tight, closed grain, like Maple, don't need the abrasive.

[Michael Mills]

I agree with Doug and Frank. I used a premixed/premade which was Qualasole for flat items (jewelry boxes).

Mylands friction polish is basically the same thing.
On the lathe (with an item maybe 8" long) you apply the Mylands a couple of drops at the time to the pad. By the time you reach the end (maybe 10 seconds) the other end is dry and ready for the next coat. When I have used it I can apply 20 coats in no more than 30 minutes with time to add new polish. I use standard shellac first and burnish with 4-0 steel wool before the Mylands; if not it may take forever to fill any pores or voids.
Make sure the cloth is wrinkle free or it will build up in the wrinkle area and leave rings on the piece.
I have never used it on anything over 3" diameter. I'm not sure it can be used on a bowl because it dries so quickly.

[Steve Huffman]

Brian, my understanding is that French polish refers to a blend of 1/3 shellac, 1/3 BLO, and 1/3 DNA. It is applied on the lathe with a cloth in several thin layers. The idea is that the BLO acts as a lubricant, allowing you to bring the shellac to a high polish before it gets too sticky. Some turners use the method because it allows them to finish a project quickly while on the lathe and move on to the next job.

I just used this method for the first time as Doug has mentioned here on a small pet urn. I got this Brian from the "Capt. Eddie" video on youtube, and I was looking for something other than the glassy look of sprayed lacquer, more like polished wood look, or more satin appearance. I didn't get the best results I had hoped for, and I have the feeling my shellac is old too if that makes a difference. I ended up with a couple coats of tung oil finish, (not the pure oil) and a couple coats did the job. Polished it up with Ren wax and got just right amount of sheen. I hope to post this urn soon....other work is killing my turning time.

[Doug Ladendorf]

Fine Woodworking had an excellent article on French polish a couple years back. If you subscribe to the online site you can access.

[Prashun Patel]

I am unfamiliar with the mix Doug references.

French polishing that I've read about and tried involves 1) padding on shellac in the 1#-2# cut range, possibly lubricated with a drop or two of mineral oil, then 2) 'spiriting off' the finish by padding on DNA to remove the mineral oil and to move the shellac around to a thin, perfect finish. It can also involve some grain filling.

IMHO, a modified French polish technique on the lathe is extremely easy. It's the way I apply shellac on turned vessels (unless I'm hvlp-ing). You just pad on thinned shellac with the lathe on. You do one pass from the foot to the rim, and keep the lathe on for a minute. Then let the shellac fully dry, and do another coat. You do this a couple times, then do the same with a pure DNA pad.

(edit): the one caveat I'll offer is that if the lathe speed is high, the shellac heats up under the friction of the pad, which can prevent a perfect shine. You have to use a light touch, low speed, and don't linger.

[Jon Nuckles]

As others have said, a true french polish involves very little oil -- just enough to keep the pad from sticking as you apply the shellac. After you get the shellac on, you then spirit off the oil with alcohol (dna unless you are concerned about denaturing chemicals and are willing to pay the taxes on pure grain alcohol). The idea is to apply a very thin but absolutely smooth surface. The pores should be filled prior to or as part of the process. As you polish, you will go over the section you are working on dozens or perhaps hundreds of times during a single finishing session. That is why it is so labor intensive when doing flat work, and it is more art than science in knowing how much pressure to apply, how much shellac to add to your pad, when to add a drop or two of oil, and when to stop and let the finish rest.
A french polish is much easier on the lathe because you only have to do a little of the work of moving the pad across the piece. While you can "body up" by applying shellac more heavily at first, the real polishing is more about moving around the shellac that is already applied than it is about adding more. If you are looking for a high gloss finish without the plastic look that poly can leave, a french polish can't be beat. If you want anything less than high-gloss, a french polish is not for you.
Keep in mind that shellac can always be dissolved by alcohol, so use coasters if you put your scotch on a french polished table top. You can also use a "padding lacquer," which is a shellac with a mix of solvents formulated to give an evaporation rate that is ideal for the padding process. Mohawk sells a couple of them that are mostly marketed for repairing finishes in the field. One has a higher shellac ratio and gives a faster build than the other. Both are very thin compared to a typical shellac cut, however, so I recommend applying some shellac first and then using the padding lacquers to get the final finish. On the lathe, you probably don't need a padding lacquer, so you can save yourself from their fumes and expense.

[Geoff Whaling]

Brian not sure if you get "Ubeaut Shellawax Glow" in the US but it will create a fine lusterous finish similar to french polishing. I have heard of a similar product available as "Dr Kirks" I think?

[Brian Kent]

For French Polish is Isopropyl Alcohol the same as denatured alcohol? I mean can I use Isopropyl Alcohol?

[Prashun Patel]

Denatured alcohol is typically ethanol. It is to isopropyl alc what naphtha is to mineral spirits. They are largely interchangeable. Ipa will slow the drying of the shellac marginally vs ethanol.

Dont use rubbing alcohol tho.