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| FP next to heel and fingerboard http://www-.luthiersforum.com/forum/viewtopic.php?f=10102&t=14793 |
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| Author: | Marc [ Mon Dec 03, 2007 9:28 am ] |
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Two areas where I spend more than half of my time on a French Polish (span. heel classicals, pumice-fill), are on the sides next to the heel and on the top next to the fingerboard. The difficulty, as I’m sure most FPer’s have encountered at some point, is getting a uniform continuous level gloss-smooth-surface running into the fingerboard or heel. For these special areas I use a very small flat muneca making figure eights staying as random as possible. A couple of problems with this technique are small radius turns and difficulty maintaining a small muneca at the proper level of shellac-alcohol for very long. I usually get close to a satisfactory result and then I hear 'tick' -- a catch or a grab of the muneca on the surface. This aggravating event creates a muneca-imprint, or cloudy area. Immediate fixing is difficult and usually results in creating undesirable swirls. So I let it dry for a day, level and start over, eventually getting acceptable results but with my patience severely tested. I'm looking for a better technique with more dependable results if there is one. If you FP classicals (or SS with the neck attached), I’m interested in hearing what method you use next to the heel and fingerboard. |
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| Author: | Michael Dale Payne [ Mon Dec 03, 2007 10:03 am ] |
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If you ever stick then you are too dry, too slow (shellac/alcohol) or you are in need of a drop of oil. As far as sheen is concerned, never worry with the sheen till all the film thickness is built and you get to the glazing process. Since I do 99% steel string I finish the neck and body while they are separate. i don't usually have that problem. However I do understand your situation with Spanish heel and I have done a couple. There is no really easy way that I am aware of to handle these areas other than to shape your muneca into a small point and use that point in these areas and work on a smaller scale. This does require more frequent loading as the area of the muneca is small and therefore the need to reload is more often. Sicking does worse than just ad marks to the film it also pulls off previously laid shellac and can embed dust or possibly lint. Learning to not over work your load on your pad will help |
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| Author: | Howard Klepper [ Mon Dec 03, 2007 10:40 am ] |
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No law against sanding and rubbing out a french polished finish. |
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| Author: | jfrench [ Mon Dec 03, 2007 10:59 am ] |
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[QUOTE=Howard Klepper] No law against sanding and rubbing out a french polished finish.[/QUOTE] Couldn't agree more. |
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| Author: | James W B [ Mon Dec 03, 2007 11:08 am ] |
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What if a person sprayed on the shellac? Is this a viable approach.I`m thinking with several coats and spiriting off maybe every 3 coats or so a pretty good finish could be had, without a bunch of rub marks.Not trying to hi-jack ,but has anyone tried this ? James |
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| Author: | Tim McKnight [ Mon Dec 03, 2007 1:24 pm ] |
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I have never been successful in spraying partly because I tried to lay it down too wet and the underlying finish wrinkled. I know a few guy who do spray it but they put it on pretty dry. |
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| Author: | DP LaPlante [ Mon Dec 03, 2007 2:17 pm ] |
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I use a pad about the size of pecan (unshelled of course <G>) and apply straight pulls next to the heel edge on the side, along the heel's edge and up and over to the other side of the heel and again on the side next to the opposite heel edge. I then do straight pulls back on either side to overlap the side pulls done previously that left off beyond the waist on the treble bouts. I also sand (360) between sessions and polish at the end.
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| Author: | Marc [ Tue Dec 04, 2007 12:27 am ] |
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Looks good DP, that's the results I like but it takes me several days (maybe even a week) to get there. I've tried the straight pulls but I always get fine streaks running parallel to the heel. Looks like you have overcome this problem. I'm interested in your technique--need some more info, hope you don't mind a few questions. Were you able to complete this in a single day? You sand between sessions with 360, how long do you wait before sanding? What do you polish with? |
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| Author: | Michael Dale Payne [ Tue Dec 04, 2007 1:28 am ] |
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excellent DP Marc I would not worry to much about streaks left in a body session as long as they are not stick marks. Spiriting-off will level these. I don't know your overall experience level with French polishing, But my experience with those new to French polishing is few understand the reason or the process of spiriting-off. Colin and myself many times have stated that once you learn to properly spirit-off there will be little if any need to sand to level your film. Anyway my point is that ridges left in a body session will be removed in the immediately preceding spiriting or stiffing session. This is one of the biggest reasons I always recommend that after the 2nd or 3rd body session that you allow the film to firm up a couple hours then spirit-off and do so after every body session there after. You don't have to wait 2 hour, I do because I want the film to gas-off really good. 20 min. is enough. But by spiriting-off after every session you build a much leveler film and very likely will never need to sand level. |
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| Author: | Colin S [ Tue Dec 04, 2007 2:05 am ] |
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Exactly as Michael said, spiriting off and the final glazing session are the key to a good French polish session. Done with the right pressure they also give a much harder than you think finish. Once I start to French polish, no abrasives are used at all. I always glue my bridge on before I finish, with my fully bolted on neck I can finish the back and sides then string it up and do a rough set up, so that I can 'tune' the top by sanding the edges and lower bou to get the result I'm after. Then I finish the top. This means that I have to French polish the top with the bridge in place. for polishing up to the bridge I use a muneca with a core of felt cut to a round fronted wedge that allows for a very tight fit to the bridge. I'm currently building a classical with Spanish heel so I'll use the same muneca up close to the fingerboard and neck heel. Colin |
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| Author: | Dave-SKG [ Tue Dec 04, 2007 3:01 am ] |
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Michael, Colin, would either or both of you please describe your technique for "spiriting off". I have had most of my problems in this area...so much so that i now generally skip this part and then take the instrument to a buffing wheel with super fine Menzerna to get a nice glossy finish. How wet is the muneca when you spirit off? and if you are "dissolving" straight grain alcohol ( that's what I use not denatured) then how does that harden the finish...it seems to me it would actually soften the finish as a result of the alcohol. THANKS! |
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| Author: | Michael Dale Payne [ Tue Dec 04, 2007 3:41 am ] |
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First Spiriting-Off is the process of knocking down boding swirls and ridges by using only the residual shellac in the muneca along with adding a few drops of what ever solvent you use. The concept is to use long straight firmish but quick strokes. All in one direction, with the grain. In other words start at one end and always stroke towards the other in a non stop pass. Glide on to the surface and glide off. Quick, firmish and purposeful. you want the solvent loaded to be wet enough that the firm stroke will not stick but not so wet that you leave a wet streak behind you. Keep in mind that while spiriting-off will somewhat polish the surface, this is not the main intent at this time of the process. Glazing is where you really develop the sheen. spiriting-off during build up is a leveling and oil removal process. if you have ever buffed shoes with paste wax, when you take the buff cloth and stoke to level the paste out, this is similar. It is import at least to me that I spirit-off one direction one time, then after the next body session spirit-off the other direct the next. This keeps the pull over alternating and helps keep the film level. If you always spirited-off in the same direction every session all the pullover would end up at the exiting end. Al C. disagrees with me here but my Grandfather taught me that the firmness of the stroke and the flash of the solvent hardens the film as you go by compressing the solids tightly together. but as Al will likely say molecular scale this is not what is happening. So scientifically I am not right about this But experience wise a firmly stiffed and glazed film is harder than one that is not spirited-off and glazed firmly |
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| Author: | Dave-SKG [ Tue Dec 04, 2007 3:48 am ] |
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Thanks Michael, O.k. So spiriting is basically leveling...Glazing is...and what technique do you use for it. i basically have been building up what I considered a nice layer of shellac over many sessions, let it harden for a good 4-6 weeks and then go to the buffer. I realy didn't see the need to level and as for "glazing" I guess I always ruined what I had already done with having too wet a Muneca? Can you give more details? Thanks, Dave |
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| Author: | DP LaPlante [ Tue Dec 04, 2007 4:09 am ] |
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Marc, as always these French Polish threads turn into simultaneous discussions about very different methods. Unlike MichaelP I have no history French polishing anything except guitars so my technique is specific to that, and grew out of my previous experience with lacquer work. So to answer your specific questions: "Were you able to complete this in a single day?" No, certainly not. My polish is a four to six week process with many bodying and leveling cycles in order to build/fill the surface. "You sand between sessions with 360, how long do you wait before sanding?" I use non-loading paper and do not attempt to completely level the surface in the earlier phase of the work, just to knock down any lap marks etc. Once the surface is well developed I usually go to 400 paper. Often I can sand the next day but often a week will go by until the next session. "What do you polish with?"
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| Author: | Michael Dale Payne [ Tue Dec 04, 2007 4:30 am ] |
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Ok.. Glazing is the process of final leveling and polishing the film. First you need a clean muneca, a thin cut of shellac and a lubricant oil. The shellac cut should be around 1# or maybe less. I preload a new inner pad in advance of this with 2# cut and squeeze out the excess so that I have a loaded but not full inner pad/ I allow it to set-up overnight in a ziplock to firm up but not harden. The process here is to smooth out any micro ridges, flow new shellac into micro recesses and thereby polishing the film. The load should be about 3 drops of 1# shellac and 2 drops of solvent and on drop of lubricant oil. I then smack the muneca firmly on the back side of my left hand. This distributes the solvent load into the inner pad and melts a little of the shellac in the inner pad. The stroke is very similar to spiriting-off though if a flaw exists in a a spot you can use a cicular motion to lay-down new shellac then come back later to glaze that area. Start in the middle and work toward the edges with attention at the plane transitions. Stroke firm and quick with the grain unless repairing a bad spot. Then come back later and do the same for the repaired spot. I think of this stroke like stropping a razor but in only one direction at a time. you want to see the vapor trail just as in boding but not last as long as it did while boding. As you do this process you will notice the sheen begin appear. Like in the Milburn tutorial I use a work light and watch for the reflection of the light bulb to come into focus. The odds are the first several attempts at this you will get a sheen that is somewhere between a satin and a high gloss, but just because you quit too soon. you can continue and take the sheen to as high of gloss as you are willing to put the elbow grease without ever touching a buffing wheel or polishing compound. but I don't have problems if you want to save the elbow grease and polish out on a buffer. you should not need to allow to cure more than a week. The solvent in French polishing is flash off as you work it. If done right you could take it to the buffer in just a couple days if that is the way you want to go. |
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| Author: | Arnt Rian [ Tue Dec 04, 2007 4:32 am ] |
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[QUOTE=James W B] What if a person sprayed on the shellac? Is this a viable approach.I`m thinking with several coats and spiriting off maybe every 3 coats or so a pretty good finish could be had, without a bunch of rub marks.Not trying to hi-jack ,but has anyone tried this ? James [/QUOTE] I've done only one mandolin this way so my experience is limited, but FWIW; it works fine. I have never done a proper French polish so I can't say how it compares to that, but the finish is holding up nicely. I have played it mostly every day for about a year and a half now, it seems plenty hard. The F5 has lots of difficult inside corners and so on, but I just worked my way up through the sand paper grits until it was done. The classic Loar era F5's had a FP over the varnish finish; sounds like a lot of work... Here's the thread where I showed pictures of it and talked a bit about the finish F5 |
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| Author: | Michael Dale Payne [ Tue Dec 04, 2007 5:00 am ] |
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Shellac can be sprayed painted rubbed or poured. I have sprayed a couple the rubbed out to satin sheen and high gloss. personally they are not as hard of a film IMO as French polished films. Some furniture makers will spray or paint a base coat of shellac and French polish over that. Shellac has been used in every form or fashion for centuries |
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| Author: | Michael Dale Payne [ Tue Dec 04, 2007 6:30 am ] |
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DP if I remember a discussion we had some time ago your method is more kin to the traditional hand rubbed lacquer application than French polish application. meaning where you lay down the shellac via rag-on process rather than amalgamate shellac as in the French polish technique. than Then a gain I may have that discussion confused with someone else. If so I apologize for the mistake in advance I do not mean any criticism of either. My only point is of the many application processes not all are related other than you can use the same media. most all will produce good finishes. There are many many ways to apply shellac. Some refer to as fast build French polish techniques. I have no problem with them as valid finish techniques. The all are viable finishes. However it seems a lot of people think that applying shellac in multiple coats with any old rag technique is French polishing. However I am at heart a traditionalist. I Have and still do hold fast to the thought that the application process of traditional French polishing builds a harder more durable film. No I can not prove this with words or scientific fact. I just go on the film I have built over many years and trying many different techniques The application process of French Polishing from my stand point can be defined as a solvent based forced amalgamation, but is most certainly not applying coats of finish but is rather building a single continuous film by melting new shellac into previously applied shellac. I have be taught and do be live that this continuous melting forging melting and forging of the shellac makes a harder film. To me this is the essence of French polishing. That in no way is to distract from the viability of any other shellac application But without this amalgamating process I can not consider other application processes to be French polishing, and due to my love of this process I feel it is important for newbies to understand that it is the process of building the film and not the fact that the media is shellac that makes it French polish. Once again I am not demeaning the appropriateness or quality of any one's application process. Just expressing my opinion of what French polishing is. |
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| Author: | DP LaPlante [ Tue Dec 04, 2007 6:40 am ] |
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Michael, I think you are indeed confusing our earlier discussion with another that you had with someone else. Other than my method of leveling it does not differ in any significant way from the traditional french polish application other than the pad (rubber, muneca) is moved in straight pulls and without the use of oil.
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| Author: | Michael Dale Payne [ Tue Dec 04, 2007 6:43 am ] |
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I was afraid I might have 
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| Author: | Marc [ Tue Dec 04, 2007 7:44 am ] |
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Thanks DP, I appreciate it. |
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