I'm about to fit a new bridge to an archtop guitar. Dan Earlewine has a good StewMac trade secrets column on how to do it with a Stew Mac bridge fitting jig, but he uses sign painter's tape and 3M Stickit Gold paper. I'd like to find a source for small quantities of either, since I don't do that much guitar work and probably would never use whole rolls of either sandpaper grit or the tape. Does anyone know a source for small quantities? I haven't seen either the paper or the tape in the local hardware... . Otherwise, I'll use regular paper and figure out a way to hold it down.
I plan to buy a StewMac Bridge Fitting Jig and then sell it after. I've fitted a couple of bridges before "freehand" and this tool, while a little pricey, is what I think I need to do a good job. It does look like something I could make for a one-off, but finding the materials and building it up seems like more time and labor than it's worth for one job. I figure that buying and then passing on the tool is a good way to get its use for a reasonable price.
BTW, Dan E. warns about the possible damage to finish from regular masking tape and I concur: this guitar has a nitro finish and when it was shipped to me the shipper used stick-it notes to mark the approximate location of the bridge. The notes left a nice bit of crazed finish under the sticky parts.
I would have removed the bridge and either removed the strings or loosened and padded the strings too. I don't like shipping or receiving anything tuned to pitch and, IMO, leaving a loose bridge in place is asking for trouble.
I've also seen an archtop guitar that had a top crack caused but it being shipped with that tailpiece left free and un-padded. I like it when nothing can move when it's packed.
I've found the 3M drafting tape to have much lower tack than the blue painter's tape.
I also like the Pro Art tape which is low tack and acid-free:
I believe the sign painter's tape Dan Erlewine uses is TransferRite. Here's a link for the 12" x 100 yards. I think it comes in 6" too:
I've used Klingspor sandpaper for a while with good results:
I don't think this is the least inexpensive place to buy it.
I just looked at my stash of tape and 3M "delicate surface" blue and white low tack both have a warning on the inside not to use it on lacquer. The adhesive must have VOC's in it.
Is Pro Art OK for lacquer?
I've used it only a short while. I use it daily on lacquer finishes and haven't had any problems. However, I take the tape off ASAP and haven't used it on any finishes with marginal adhesion. The only problem I've had is in taping clean edges for finishing. The tape edge is a bit rough. I don't know if this is typical of just the batch.
The link I gave you is for the Pro Art masking tape. I actually use the Artist's Tape:
You don't need no stinkin rolls of stuff to do this.... :) Please note smiley face....
I wanted to post a link to a toot on my site for how I floss/burnish/fit stinkin bridges but for some reason beyond me my site is not giving up the links to the individual pages... I'll have to look into it when I have more time...
But for now if you want to go to Hesh's site and click on "Luthier Info" near the upper left hand side of the home page. Once on the "Luthier Info" page click on "Fitting Bridges", I think it's the very first one and you may see some ideas that will help you out.
I only use one standard piece of paper, sandpaper, and regular masking tape that I typically will stick to my shirt a few times to detack the stuff.
These days I do things differently and much faster but this method works, does not damage the guitar, and does not require a $30 roll of self-stick sandpaper.
Hope this helps!
Hesh, I've been to your site before and picked up lots of useful information. Thanks for the public service!
I don't have self-stick sandpaper as, just starting out, I found the premium for PSA paper stiff. I bought a good quantity of good quality sandpaper from Klingspor, as well as micro finishing papers and micro mesh pads in several sizes. The micro mesh pads are miraculous and I've used them for everything under the sun (including fingernail ridges).
However, I worry about the method I use to attach these papers. On radius blocks and fingerboard levelers I use rubber cement. Rubber cement gives good adhesion, adds another step, requires waiting, and is messy when new and lumpy soon after. I am forgetful and leave the top off and it dries out.
When I fit archtop bridges I cover the area with wide masking tape (de-tacked), then double sided tape, then sandpaper. It works, but I worry that the three layers isn't transmitting the shape of the top exactly. Eyeballing gave me haphazard results so I acquired the StewMac Archtop Bridge Fitting Jig. The results are much better, but fit still not perfect. I know the top flattens under string tension which would make the bases over-radiused, but I worry that the three layers might also be a variable. Is this a real worry?
Not sure if three layers of tape skews the results or not. When we do neck resets, an area where a perfect fit is the goal, we use one layer of tape and when the tape is removed the fit is what we had hoped for.
I always wonder about the quality control on tapes in terms of is there a truely uniform thickness. Seems that if there is not, and that's entirelly possible, multiple layers of tape additionally skew the results. On the other hand maybe quality tapes are pretty uniform. Maybe it's time to start measuring the thickness of the tapes that we use to see what the answer to this question might be.
For archtop bridges I'm not sure that an archtop top deforms to the same degree that a typical acoustic guitar under string tension deforms. My guess is that it does not because the top is way thicker, the bracing is different, and a archtop has slightly different physics in a number of ways over a standard acoustic. As such I floss/burnish/fit archtops (and mando) bridge bottoms the same was as in my toot and don't worry about what happens under string tension.
After all a decent fit from the process is nearly always way better than how the instruments were manufactured or come in the door. As such I think that you are OK but again my tops are only protected by the sandpaper itself and no additional layers of tape. I'm careful, never bear down and let time and the paper do the material removal.
I love micromesh abrasives too and here is a trick for you. On the stinkin guitars that I build I have this thing against using anything pl*stic anywhere on the guitar. So I use wood pins and sometimes BRW wood pins if the color match makes it work AND if it's appropriate for the specific instrument.
When using wood pins take your pins, micromesh pads, and cordless drill and get comfy in front of your favorite college football team's game.... and chuck a pin in the drill. Spin the drill while holding a micromesh pad on the part of the pin that shows. Repeat through all of the grits and in no time your pins will look like they have finish on them! It's easy, fast, and I like the results. I've used micromesh on bridges and tuner buttons too with great results. Great stuff!
Thanks for the help on sorting out my problems. That's a good trick using the drill and pads on the bridge pins. I'll try that technique on the new set of bone pins I'm about to install. Do you have a problem with the drill jaws imprinting on the pins? A large collet might be helpful.
I always use Micromesh on nuts (I only install bone). Makes for a nice gleam. I'm using pads that look worn out but still do the job.
Tape Uniformity: I'm sure tape is like any other manufacturing process. Some companies have state-of-the-art equipment and others hand-me-downs, especially overseas. You know they still make '57 Chevy's in Brazil, right? Chevrolet sold them the entire line of tools and forms.
All tape manufacturing machines have operating tolerances that drift over time, requiring adjustment. The newer machines have tighter tolerances due to technical progress as well as a lack of wear-and-tear. Every tape manufacturer is producing to a standard so they sample their output at specific intervals and, when out of spec, make adjustments. Quality control people collect data on mean dimensions and standard deviations and reject anything that falls outside the specified window, you know, x= .004" +/- .00015 (x̅ ± 2s ) or such.
The older machines require more attention and (this goes for all companies) if their technicians aren't well trained and on-the-ball there will be sub-standard product going out the door. Companies minimize costs by selling substandard product to companies who rebrand the stuff, sell it in bulk, or OEM it.
The better stuff is going to be more expensive though not at much as we might expect. The more modern company's state-of-the-art equipment produces more product per hour with less waste and the newer machines break down much less often. When machines break down, they stop the line, lowering daily output and raising the marginal cost of each unit.
I would expect the companies selling premium products to also have better quality control over their input materials including paper, chemical purity, etc as well as having the technical staff to incorporate the latest technical advances that minimize out-gassing, acidity, surface delamination, etc. Obviously, if the adhesion of the tape exceeds the adhesion of the finish delamination will occur regardless of tape quality.
So I guess the short answer to your question is that the better stuff, like 3M products, will be more uniform. 3M, however, may sell many different tiers of products with different standards for different purposes. In this case, the problem is knowing the product line as well as where diminishing returns set in. Beyond a certain standard there may be no improvement for our purposes as long as the tape has the adhesive properties appropriate to the task. I'm sure you, like me, have binding tape, blue painter's tape, masking tape, drafting tape, transfer tape, and artist's tape - all listed in terms of decreasing stickiness.
The Pro Art Artist's Tape I mentioned is on probation because of the edge serration I mentioned. They make this stuff in sheets and cut it into strips so I'm guessing the problem is dull knives, indicating either a lower standard, lower quality control, or a substandard unit that slipped through. I think the 3M Drafting Tape is better but more expensive.
I've not seen an marring on the pins from the drill chuck but I also, at times with softer woods instead of say bone pins, may wrap the tapered part of the pin in one layer of electrical tape for padding. The drill and micromesh will make bone pins look so very shiney that some folks might think that they are plastic.
I have a very good client and now friend who is a master jewler. Upon picking up his MK series Gibson that I had made a bone nut for he would not believe it was bone until he got it back to his shop and did some tests under high-powered magnification. Kind of like ebony binding that looks like black plastic too once the guitar is finished gloss lacquer....
I was using micromesh and loving it until David Collins introduced me to the idea of buffing nuts. The outcome is the same but the buffer is way faster.
We used to use the blue tape until it reacted with lacqer and ruined our day.... Now we are using standard 3M masking tape, often detacking it, and never, never leaving it on finish overnight.
Robbie thanks very much for the info on the manufacturing process for tapes! I can tell that you have great knowledge of process engineering and manufacturing in general.
Is that buffer solely for nuts? How many grades of compound do you use? I've got a spare motor with a long shaft I can re-purpose!
You might want to look for the 3M drafting tape which has lower tack than the masking. Then again, if you're de-tacking it on your shirt, masking may be more versatile.
Hope I didn't bore you. Sometimes I feel the need to sum up what I know to clarify my understanding. I have to say, I learned quite a bit by teaching. Student confusions sometimes had antecedents in my own understanding.
In my econ doctoral program we had to take 12 courses in statistics, advanced mathematics, and econometrics.. We had case studies from all walks of life, including manufacturing.
You may have heard about the Six Sigma program that GE, Home Depot, and others use. It is based on the idea of reducing manufacturing defects (or other problems) by insisting that variance among units be so small that only those more than 6 standard deviations away from the mean are substandard. This reduces the failure rate to .0001%.
As a friend used to say derisively, "Fascinating! Tell me more" ;-p
Sorry for the delay in getting back to you - I took a break to get a ride in an ambulance and sample the not-so-fine cuisine.... of the local University hospital for a few days.... :)
But I'm fine and back now.... ;) Bring it on..... ;) cough, cough....
Yep the buffer is just for nuts, saddles, anything that we want to take the fine scratches off or make shiny as all get-out. The compound is only one grit for us and just plain-ole hardware store buffing compound. It works great if we sand with 320 first and then go to the wheel. I like to go to the wheel a bit early in so much as I can then see the scratches that I want to tackle with the 320 grit better.
I know Six Sigma well my self and was once certified, not to be confused with being "certifiable...." at a couple levels. While at GE as you mentioned Jack and GE were committed to Six Sigma as were and are many of the big name companies. It took huge amounts of my life/time and was not unlike getting another degree with lots of studying, tests, projects, etc.
Although Six Sigma, the original ideas of Demming was best suited for manufacturing we attempted to apply it to software code....
For everyone else as Robbie rightly said Six Sigma is a highly structured discipline that permits people at different certification levels i.e. green belt, black belt, and master black belt to take on projects for their employer that will apply a highly structured methodology with the goal being to improve the quality control of processes AND products.
We applied it to jet engines, light bulbs, locomotives, and as I mentioned software code too. It's also been applied to dealing with clients as well with the hope being greater client satisfaction and greater efficiency in pleasing the clients.
When I started with Six Sigma and absolutely hated the time that I had to invest in it as it was mandatory for everyone at GE I could not see the benefit. Now with some of my own projects behind me and having worked on many other projects I'm a believer.
It got it's start with Demming who after WWII had some pretty strange ideas about how to reduce manufacturing defects to less than 3.4XXXX per 1,000,000 operations. We in the US thought Demming was nuts so we sent him to Japan to help rebuild, from the ravages of the war, companies. Some of these companies became legendary for quality as a result of Demming, Six Sigma, and of course their own pre-existant cultures when it came to the quality of work that one does. Little names such as Toyota, Mitsubishi, etc. were all Six Sigma organizations and as a result their products are widely believed to be very well crafted.
Toward the end of my time in the conventional work place I got involved in acquiring/assimilating companies/corporations and we still employed Six Sigma methodology to study and measure compatibility, profitability, market share, etc.
Kind of funny that when I first was told about Six Sigma I was screaming and kicking believing it was utter BS. Once I saw it working for us and understood how to make it work for me I became a believer.
In a nut shell though it's simply a highly structured methodology for measuring defects, devising improvement, applying the improvement, going back in short order to measure the results of the change, and then documenting what was done so that others may benefit in the future. All of this with a methodology that guards against and to some degree prevents the tendency of we humans to want to breath our own air and not always look at defects/change/etc. honestly.
Robbie in my home shop I have a $20 Harbor Freight grinder with buffing wheels, on both sides to keep it balanced, and it works great for buffing nuts, saddles etc. It's also faster, saves sand paper, and the results are the best that I have ever seen including even shinier than micro-mesh.
Hey Hesh...sorry to hear about your illness. Hope you're better! That had to suck. As coincidence would have it, I have bronchitis and benign paroxysmal positional vertigo.
Thanks for the Demming info. I knew a little of the Japan story. Thanks for sharing. One thing I find interesting about Six Sigma is how they took a statistical method and clothed it with a human interface with achievement levels (green belt, etc.). I guess it made the concept more palatable while making its mastery a competitive sport.
The orange Harbor Freight buffers? I have two of the 6" ones...wish I had gotten the 8" ones. The 6" have 1/2" spindles while the 8" has a 3/4" which would take the SM and LMII pads. I think Grizzly has 1/2" pads though.
I need to put them on pedestals to get better access. I have pads for 3 grades of compound and a wire brush, but I originally set this up to clean and polish old house brass hardware so need to revamp.They're a little fast...do you use a dimmer or something on them?
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