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Tips on French polishing
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=25471		 Page 1 of 2
Author:  Beth Mayer [ Wed Jan 13, 2010 1:48 pm ]
Post subject:  Tips on French polishing
Greetings! this is my first time in the forum. What a great resource. I am looking for some french polishing tips. I am doing it for the first time on a steel string acoustic and have found two problems so far. The first is that, unless I add oil to my pad, the #2 and #1 cut seems to get sticky right away. When I feel the pad, there is some wetness to it, but the perimeter of the wiping surface feels dry and stiff. And then it doesn't produce the smooth, shiney surface I expect. Second, I noticed after about 3 coats of the #1 cut shellac with a few drops of olive oil (which smooths the application nicely), as it has dried I now have a couple of blotches of opaque finish. I'm wondering if that's due to the oil?

Any advise will be much appreciated! I love the look and sound of a well done french polish and have a small shop not suitable for spraying so I want to learn to do it well. Have watched a few techniques on YouTube and they all teach it differently from eachother, as did my mentor Norm Haight.

Beth
Author:  Hesh [ Wed Jan 13, 2010 2:09 pm ]
Post subject:  Re: Tips on French polishing
Hi Beth and welcome to the OLF!

Here is a link to a tutorial that Michael Payne did to perhaps keep you busy until Michael and others come along to answer your specific questions:

http://luthiersforum.com/forum/viewtopic.php?f=10117&t=21980

Robbie O'Brien who teaches French Polish at Red Rocks Community College and who also has the distinction of having survived having me in his class... :D is also a member here and will hopefully weigh in. Robbie has some excellent DVDs available and I believe that his FP method is available on DVD.

Welcome aboard!
Author:  Michael Dale Payne [ Wed Jan 13, 2010 2:26 pm ]
Post subject:  Re: Tips on French polishing
Beth,

High I am sorry I have not found the time to finish the tutorial I got started. it is un common to not need oil on your muneca when bodying. It is the nature of the process to apply the shellac dryier than most first assume. that means without oil the muneca will want to stick if it comes to a stop. a couple drops of oil the last thing you do at each reload then tap on paper or the back of your glove to force the new load into the inner muneca and you should be good to go for 4 or five min. or so. If you do read what I have in my tutorial so far pay attention to what i say about the viscosity of the inner muneca. this is one of the main keys to getting the muneca to work properly. the next paragraph explains what i am speaking of. Do not worry about oil getting trapped in the shellac it will always rise to the top of the last applied body session and will be removed when you spirit-off. I recommend spritting-off after every body session. This helps build and level surface as you work and removes the oil from the previos body session.

Something very important to understand about how the muneca should work; is that each time you load the muneca with a fresh load of shellac and alcohol; you are not loading the outer surface of the muneca to make the outer surface wet or the inner muneca wet. You are loading the outer surface of the muneca then tapping the new load into the inner pad. This new load partially melt the semi-hard residual shellac in the inner pad and forms a wicking channel for the semi melted residual shellac to follow through the outer pad and on to the surface as you body, spirit-off and or glaze. For your muneca to work properly the residual shellac in the inner muneca needs to be semi-hard about the viscosity of soft taffy. If the shellac in the inner pad is wet at time of use; the muneca pulls off more shellac than it leaves behind and will also lead to high friction sticking.
Author:  Michael Dale Payne [ Wed Jan 13, 2010 3:23 pm ]
Post subject:  Re: Tips on French polishing
I forgot to answer your question about opaque blotches. I am not sure you really mean opaque as that would indicate zero transparency. I will assume you mean two blotches where the appearance is muted or gunky but still somewhat transparent. With out knowing all things about the processes you are use and shellac and oil you are using as well as seeing the blotches for my self I can't be to certain but can say this is usually cause by a contamination. If the areas are slightly cratered the contaminate is not allowing the shellac to build there this is a common of silicone and or lanolin contamination. If the surface is level but the blotchy areas are less transparent that the rest of the surface then this is common of entrapped contaminate that mixes with the shellac
Author:  Beth Mayer [ Wed Jan 13, 2010 3:25 pm ]
Post subject:  Re: Tips on French polishing
Hi Hesh and Michael,

Thanks so much for the quick and informative replies. Michael, I read your tutorial and it helped a lot. I need to get the wool roving, because I have just been using a 4/4 gauze sponge folded into a wad as my pad. I am anxious to try your inner pad prep method. Also, I haven't been doing the "spiriting off" between sessions.

Hesh, I spent a lot of time on the forum last night just reading the many threads and got a lot of great information from your posts. You are awesome. I know I'm going to learn some incredible things on this site.

Beth
Author:  Michael Dale Payne [ Wed Jan 13, 2010 3:29 pm ]
Post subject:  Re: Tips on French polishing
kohola strings wrote:
Hi Hesh and Michael,

Thanks so much for the quick and informative replies. Michael, I read your tutorial and it helped a lot. I need to get the wool roving, because I have just been using a 4/4 gauze sponge folded into a wad as my pad. I am anxious to try your inner pad prep method. Also, I haven't been doing the "spiriting off" between sessions.

Hesh, I spent a lot of time on the forum last night just reading the many threads and got a lot of great information from your posts. You are awesome. I know I'm going to learn some incredible things on this site.

Beth


the gauze will work fine. The wool roving wicks a bit better at hiviscosity that the gauze but both will do the job. Most people new to French polish try to work far too wet and don't change their outer pad near often enough.
Author:  Beth Mayer [ Wed Jan 13, 2010 3:35 pm ]
Post subject:  Re: Tips on French polishing
Okay, then I'll use the gauze but prep the inner pad and be sure to change the outer more. Regarding the opacity, the surface feels smooth over the area, and you can see grain through it but it has a cloudy cast to the finish. I'm not sure what could be contaminating it...wonder if some property of the cheap gloves I was using (drug store first aid variety that I was trying to get rid of). I'll try to get pictures if it persists after I begin using your method of FP. Thanks again!
Author:  Michael Dale Payne [ Wed Jan 13, 2010 3:43 pm ]
Post subject:  Re: Tips on French polishing
kohola strings wrote:
Okay, then I'll use the gauze but prep the inner pad and be sure to change the outer more. Regarding the opacity, the surface feels smooth over the area, and you can see grain through it but it has a cloudy cast to the finish. I'm not sure what could be contaminating it...wonder if some property of the cheap gloves I was using (drug store first aid variety that I was trying to get rid of). I'll try to get pictures if it persists after I begin using your method of FP. Thanks again!


Silicone and or lanolin on cheap gloves is a possibility. I hope that is not the case. Does not sound like it or ther would be a noticible ridge around the blotch. What you describe almost sound like moisure intrapment. Odd to happen when French polishing. If you can Spirit-off that area till the blotch is gone, and rebody. If it goes away then all is good.

That said if it is silicone then you have issues that will not be easy to resolve as it is near impossible to get rid of silicone because it is constantly migrating through the wood.

remember allowing the inner muneca (inner pad) to gel to the consistancy of soft taffy is important to get the right wicking action and shellac trasfer.
Author:  Michael Dale Payne [ Wed Jan 13, 2010 3:49 pm ]
Post subject:  Re: Tips on French polishing
Beth, is it possibel that sweat droplets were boddied over?
Author:  Beth Mayer [ Wed Jan 13, 2010 4:06 pm ]
Post subject:  Re: Tips on French polishing
Maybe, if the glove had a hole in it, because my hand does sweat in the glove. Also, I was not gloved on my opposite hand, so maybe from holding the body with that hand?
Author:  WaddyThomson [ Wed Jan 13, 2010 4:15 pm ]
Post subject:  Re: Tips on French polishing
When bodying with gloves on, I have noticed some spots, and discovered that my hand was sweating so much that it was dripping from the lip of the glove at my wrist, and onto the surface of the guitar. I now stop and take off the gloves every 30 minutes or so and dry my hands. Another trick is to put some paper towel around your wrist under the edge of the glove to wick up the perspiration. Those spots are usually small, or become streaks if you don't see them right away. I have also gotten splotchy areas when I did my spit coats with darker shellac, and was filling with pumice. I think what happened was that I was too aggressive with the pumice in one area at a time, and pumiced through the spit coats. This was on my first guitar. On subsequent ones, I have spit coat with blond or medium blond shellac. If I want to add color, I polish with the darker color.
Author:  Michael Dale Payne [ Wed Jan 13, 2010 5:00 pm ]
Post subject:  Re: Tips on French polishing
One more thing I will mention though I don't think it is related to your issue. Anyone using olive oil; be sure it is Extra Virgin. I found out the hard way a long time ago that the leafs and stems of the olive tree have lots of stuff like tannic acid that can inhibit good adhesion.

Extra virgin olive oil is (supposedly) only pressed olive fruit in press that never see anything but the olive fruit. Virgin olive oil nay contain extract from leafs and stems but only from olive trees. Plain old olive oil may be pressed in presses that see al sorts of fruits plus the processors may ad flavoring.

Now the really bad thing is there are many unrepeatable producers making bottles as Extra Virgin that are not.

I switched to pure walnut oil a long time ago and love the stuff. All this said there and those that use every thing from baby oil to olive oil with out issue.
Author:  Beth Mayer [ Wed Jan 13, 2010 5:09 pm ]
Post subject:  Re: Tips on French polishing
Mine does claim to be Extra Virgin, but you're right that there may not be honest labeling. Where do you get walnut oil? Thanks, Beth
Author:  Michael Dale Payne [ Wed Jan 13, 2010 5:13 pm ]
Post subject:  Re: Tips on French polishing
kohola strings wrote:
Mine does claim to be Extra Virgin, but you're right that there may not be honest labeling. Where do you get walnut oil? Thanks, Beth


At HEB or most any top end grocery chain. labeled as "Pure Walnut oil" or 100% pure. As the nut its self is deshelled prior to pressing and most walnut oils are pressed here in the states in maufactured press exclusive to the wanut oil industry it is easier to trust as beign pure. I have never had a single issue with many years of use now.
Author:  Beth Mayer [ Wed Jan 13, 2010 5:40 pm ]
Post subject:  Re: Tips on French polishing
Michael, any problem with switching to the walnut oil once I've already begun the process with the olive oil?
Author:  Michael Dale Payne [ Wed Jan 13, 2010 5:43 pm ]
Post subject:  Re: Tips on French polishing
kohola strings wrote:
Michael, any problem with switching to the walnut oil once I've already begun the process with the olive oil?


None at all.
Author:  WaddyThomson [ Wed Jan 13, 2010 5:54 pm ]
Post subject:  Re: Tips on French polishing
Another nice thing is that Walnut Oil does not go rancid with age, like Olive Oil does. It will keep a long time, just fine.
Author:  Michael Dale Payne [ Wed Jan 13, 2010 6:00 pm ]
Post subject:  Re: Tips on French polishing
Beth! There was one thing I read in your original post that I forgot to address. When bodying ( buildinig up the film thickness) your film does not need, infact should not be high sheen. It should have good transparancy but a matt like reflection. the sheen does not come untill you start glazing. You said that you spirit-off after each body session just like I do. That will polish the film some. But it really is not important at all during the film thickness building process that the fill appear high sheen.
Author:  Beth Mayer [ Wed Jan 13, 2010 8:13 pm ]
Post subject:  Re: Tips on French polishing
That's good to know, because I was expecting it to start being glossy as I built it up. Actually I may have misspoken before, because I have NOT been doing the spiriting step, so I wonder if that won't make a big difference in the results as I add that step in. Thanks again for all your input. I'll update you on the opacity thing...hopefully that will just go away as I proceed correctly with the process. A couple of things I thought of today and wonder if they may relate to the appearance. One is that although Tucson is warm, our house has been pretty cool (lower 60's) and I was polishing inside the house. Could cold cause it to look opaque? Another thought was that 2 you tube videos on FP had included oil sanding with 800 grit between some of the sessions, and I did do that twice...could that have caused a problem (I notice you don't talk about sanding at all).
Author:  Michael Dale Payne [ Fri Jan 15, 2010 11:32 am ]
Post subject:  Re: Tips on French polishing
kohola strings wrote:
That's good to know, because I was expecting it to start being glossy as I built it up. Actually I may have misspoken before, because I have NOT been doing the spiriting step, so I wonder if that won't make a big difference in the results as I add that step in. Thanks again for all your input. I'll update you on the opacity thing...hopefully that will just go away as I proceed correctly with the process. A couple of things I thought of today and wonder if they may relate to the appearance. One is that although Tucson is warm, our house has been pretty cool (lower 60's) and I was polishing inside the house. Could cold cause it to look opaque? Another thought was that 2 you tube videos on FP had included oil sanding with 800 grit between some of the sessions, and I did do that twice...could that have caused a problem (I notice you don't talk about sanding at all).


I never touch a single French polish finish with any abrasive. That said i doubt that the sanding cause your issue.

I use the spiritting off process after every body session to build the film level as I body. the spirit-off process melts over ridges left from the figure eight motion of bodyng. and removes the last sessions oil. this process is done with a high alcohol / low shellac load along with just one drop of oil to prevent the muneca from sticking as it first approaches the surface. The spirit-off stroke is a straight quick firm but not to firm stroke. Starting at one end and moving toward the opposite end gliding on and off the surface with out stoping. The stroke is kin to the motion a shoe polisher uses when buffing but in one direction this session and the oppsite the next session. Following this process after every body session as set up for about ten min. will build a level film that needs no level sanding.

I then glaze and spirit-off to polish the film to what ever gloss I wish to take the sheen to. I have in the past buffed out with a power buffer after the film has cured a couple of weeks but normally I contiue glazing to get to my desired sheen. You can reach as high gloss of a sheen as you desire by glazing. It is just a matter of how much glazing you are willing to do.
Author:  Beth Mayer [ Fri Jan 15, 2010 1:01 pm ]
Post subject:  Re: Tips on French polishing
Awesome advise, Michael! Thanks. I will be gone this weekend, so no plans to resume FP but next week will go back at it. I'm really glad I asked about the sanding....I've been doing that :(
Author:  windsurfer [ Fri Jan 15, 2010 1:05 pm ]
Post subject:  Re: Tips on French polishing
What are the advantages of using Olive or walnut oil ?

For furniture work I was taught to use a light mineral oil such as 3:1.

-jd
Author:  Michael Dale Payne [ Fri Jan 15, 2010 2:06 pm ]
Post subject:  Re: Tips on French polishing
You want an oil that is light and prety much non drying so that it will not entrap in or mix with the shellac. You want an oil that has zero aditives that may contaminate the shellac. The ony reason you use oil at all in French polishing is to reduce the surface tension between the muneca and the previouly apply shellac. If you use mineral oil be sure it has no additives.
Author:  Tim McKnight [ Fri Jan 15, 2010 9:50 pm ]
Post subject:  Re: Tips on French polishing
Michael,
I have used walnut oil for a number of years and feel it gives [me] better results than olive or mineral oils. I also had the understanding that walnut oil is also considered a drying oil and that it can mix or polermize with the sheallc to some small degree.
Author:  WaddyThomson [ Fri Jan 15, 2010 11:37 pm ]
Post subject:  Re: Tips on French polishing
Walnut Oil is a drying oil, but it dries very, very slowly, and I would think that leaving it in the mixture might cause extended drying issues, though I could be wrong. Once you add oil to the mixture, though, it, sort of, becomes varnish, does it not?
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