Official Luthiers Forum!

For those who use a french polish finish. How many body session do you use? Milburn says six to eight, as I've found out there a lot of work in between six and eight. Is there a certain amount or are you looking at the finish itself? I'm on my fifth and I'm using both arms, man they are sore, but it's very rewarding. So far so good, in-fact coming out way better than I could have imagined.

Thanks

Peter

Well if your arms or sore then you may be rushing your self a bit. You may be better served to take your time.

In truth there is no given amount of body sessions. 6-8 is pretty typical for a guitar with a 2# cut if you have done several guitars and are proficient in your coverage.

Some guitars I do will have 6 some 12 depending on how deep I want the film and the viscosity of the shellac at time of application.

Yes French polish is a process that requires elbow grease. That is the nature of a hand rubbed finish.

I dont't ever remeber sayin that French polish is the physically easiest finish.

Of course as you build up the finish with application and leveling cycles (sessions if you will...) there is also the potential of the film becoming  more uneven. Experience and judgement dictate the "optimal" number which will produce the best result.

First off I do not recommend level sanding. if spiriting-off is done often and properly then there is no need to level sand.

That said I have over 38 years of experience to draw on. A first or 3rd timer may not be able to successfully build a level film with out leveling, so I am not that critical of those new to French polishing that level sand. But like Colin I never touch my FP with abrasives other than the occasional polishing compounds on ultra high gloss buffing. So I can not agree that building extra depth is a cause of uneven film thickness. Rather the learning curve is the cause.

I'm stiffing and spiriting between body sessions. It looks level to me, would you see ridges if it's not and while I have you Michael, can I use the 1 lb cut for glazing?

Thanks

Peter

If you are stiffing and or spirit off between each session you should build fairly level. If I remember the Milburn tutorial said to spirit off every third session but I have always spirited-off between every session to insure a level build. That said spiriting-Off technique is critical to achieve this. Learning to glide on and glide off with moderate pressure and always the same pressure will go a long way toward building a level film. If your technique is less than consistent then you can actually end up removing film thickness or causing a valley in your film.

Sounds like all is going well for you.

Yes, as shown in the Milburn tutorial Glazing requires a lighter cut. If I remember right, the Milburns use the 1# I do as well

Thanks Michael, I do appreciate the input and advice.

Peter L

I really did not answer your question on would you see ridges if unlevel.

Not nessassarily it is possible to over body in one area and under body in another when you spirit-off you would remove ridges but you could still be thicker or thinner is some areas. This is why it is important to stay in focus of where you have been and be consistent with your build by not over working in one area more than others.

But this is really not a huge deal unless you get carried away.

Also if your muneca is too wet with shellac or too dry, both cases can actually take shellac off the body. An over used or dirty outer pad will also remove more shellac than it lays downs. Staying on to of your load and changing outer pads soon enough will help.

Michael, as I have been doing this for at least 25 years, I don't think experience is the factor here, just a difference in technique. True, this might be trouble for someone starting out but it has become part of the regimen I developed long before there was much information genrally available. It also differs from the "norm" in that I neither use oil or any other additives. Just shellac and alcohol.

I've been told by long time owners of my guitars that my finish is quite tough and not prone to many of the typical problems of French polish.....as for the appearance check out the photos of my Torres copy in the thread on the Romanillos book.  

Best

I hope I did not sound like I was getting on to you . Was not doubting your skill level at all.

My point was un-level surface means either over working areas , poor load management or inconsistent coverage pattern.

I have done some experimenting with no oil, I use far less than most tutorials call for. Personally I think that maintain a good load and regular outer pad changes can allow you to cut way back on oil or as in your case maybe eliminate it. That said when glazing I find a very small drop of oil quite the aid in the polishing process. but then I am accustom to using a small amount of oil.

This past summer at the Romanillos course we were sitting around and discussing our French polishing technique....they were so varied that it sounded like we were all talking about something different. I think it is important for folks starting out to know about the many variables as they develop their skill.

 

Now there is an interesting idea.  You guys with different methods could post comparative notes on successful alternatives to, say, the Milburn Method, which, as I read it, is fairly traditional, and is posted on the OLF Tutorial Page.  And post them as variables to French Polish Methods on the Tutorial Page too.  Wouldn't want to create work for anyone, , but it would be better than doing a complete tutorial of each separate process.  Just an idea.

Now, don't hold back if you feel drawn to do complete tutorials on your own.  I would be willing to read them all and make my own comparisons.  One thing I would be interested in knowing, is how you maintain your regionality when you are doing the bodying sessions, getting the bit of overlap required to give good coverage without causing too heavy a build-up in the overlap areas.  Does the Spiriting Off process take care of those overlaps?

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Considering I have been build guitars for less than ten years, it is easy to figure out that most of my 38 years experience is not on guitars.

I learned in my Grandfathers furnishing and cabinet shop. unfortunately he did not give me the chance to learn varied methods. but what he did give me was a wealth of understanding of the media and how to use it.

I do have a question for you. in your previous post it could me rightly or possibly wrongly assumed that you are of the belief that oil affects the films hardness.

So Do you believe that Walnut oil, extra virgin Olive oil or other appropreate oils used in small quantities affect the hardness of the film?

I have to say I do not. The oil rises to the top of the film between each session and is removed in the stiffing and or spiriting process. It does not chemically change the shellac as it does not bond with the shellac.

I don't mean to challenging you on this, Just curious to your thinking on oils since you do not use them.

overlapping and over working are two different issues. overlapping is required. over working is when you stay in one area over and over and over.

Lets take a top for an example:
I start every session at the butt end of the top and work my way around the lower end profile to the neck joint the work my way back to the butt end overlapping each swirl by approximately half the arc of the swirl. I follow this pattern till I have one half completed the repeat for the other half. this is then one session on that top. unless I had a spot that did not take the shellac for one reason or another I do not back track within that session. If there was an area that did not take shellac then there is a problem there that needs addressed.

A second point to this is I pay major attention to the vapor trail or cloud at all times. if it starts to disappear too quickly I know it is time to reload my muneca.

All I have Michael is anecdotal info from owners of my instruments that, unlike some others they have owned, my finish was less prone to some of the typical problems of FP........the non use of oil could be a factor but I'm not claiming that.

I mentioned it to make a distinction between my technique (including level sanding) and the ones more commonly used which include oil,  other additives and spiriting off as you have described. 

I don't claim to know as to whether the oil affects the hardness or not, however it seems to me, as I am able to control the movement of the pad through cut, pressure and technique that oil is not only incompatible with the shellac and alcohol mix it is also not needed.      

Best!

Thanks Michael.  That's exactly what I wanted to know.  Slow as it is, my time is coming, and I want to be ready.  I'll start some practice sessions before too long to see how well I understand.

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Here's another difference in my technique I should note after reading your last post Michael.

I do not use a swirl or figure eight motion to apply the material. Mostly I use straight pulls on the top, back, sides and neck with some special techniques for the heel and peghead slots.............now I'm really out in left field....<grin>

That is Ok DP everybody has quirks

How long do you guys wait in between sessions before starting another session? Also how many applications of shellac are considered a session?
                           James

_________________
James W Bolan
Nashville Tennessee

I wait 2 hours between sessions. Though you could add a session with in 15 or 20 min with no problems. One application is one session. Back tracking during a session is asking for problems of lifting freshly applied shellac and the friction increases thereby adding to the risk of your muneca sticking. (big headache there for a newbe)

French polish is a process of amalgamating new shellac into previously cured shellac making a single and continuous film of shellac. If you plan on attempting a French polish finish you need to get rid of the idea of applying in layers. You do not apply layers. you build one amalgamated film by kneading or melding the new shellac into the old.

Thanks Michael.It seems the first time I French Polished I had A few Problems.I`m pretty sure waiting between sessions will be helpful.
                               James

_________________
James W Bolan
Nashville Tennessee

I forgot to ask,do you spirit off right after each session or wait until just before the next session?
                        James

_________________
James W Bolan
Nashville Tennessee

Let it harden to the touch (3-5 min) before spiriting off.

The five most common errors newbies to French polishing make are:

1. Poor muneca preparation:

you need to properly preload your inner pad 24 hours in advance so that it has a ready to dissolve reservoir to draw from once you start.

2. Poor muneca loading:

You need to learn that the shellac being laid down is coming from the inner pad. The shellac you add to the muneca at load up is a wicking agent. If yo body with too wet of a muneca the wet shellac on the pad will actually pull shellac off the body. If too dry then the inner pad does not properly release shellac and your muneca wants to stick Read carefully on the proper loading in the Milburn tutorial. The give a good explanation of how to tell if you load is too wet or too dry.

3. over working the body and or glazing sessions:

never go back over a bodied area while tacky this just builds in problems. One, shellac can bridge leaving miro-voids in the film if bridging occurs. Second the friction is much greater as shellac starts to tacky up. Sticking even with a properly loaded muneca is likely.

4. failure to maintain a efficient outer cover.

As your outer pad gets loaded up with a lot of shellac it will not transfer shellac as well. That said the first load or two with a new outer pad is not at is most efficient either. you don't want a band new outer pad every session but if you pay attention you start noticing the drop of of transfer then you know it is time for a new pad to be broken in.

5. Patience:

This is a build up hand rubbed finish at first the build will seem slow but it will get there faster than you think at that point. There are a lot of fast build FP techniques out there. I have tried several of them. I personally feel a traditional build method builds a better and harder final film. You Dad was right. Nothing worth having comes real easy. In the traditional method, every step of the process is as important as the others. take the turtles path and you will have a finish for a life time or three.

In my books French polish is the greatest all round finish for furnishings to wood instruments and has been for hundreds of years. There is a good reason it is still practiced, used and even coveted by wood lovers around the world. it is simple. effective and beautiful.

Those pointers are worth a lot to those of us who are beginners at all this.  Great information.  Thanks Michael.

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Michael-

Thanks bunches for this info - great stuff for a newbie like me.

_________________
John Lewis
Wannabe builder owned by 2 crazy dachshunds