Page 1 of 2 12 LastLast
Results 1 to 25 of 33

Thread: new top F hole repair

  1. #1
    Registered User
    Join Date
    Oct 2015
    Location
    Howell, NJ
    Posts
    133

    Default new top F hole repair

    I was cutting the F holes out with a coping saw and a piece split off. The coping saw has a 16TPI blade and it seemed way too aggressive. It would stick every time it hit the darker grain. This may be 2 different questions, but they are related.

    Is there a better type of saw or a better blade to use for cutting the f holes. I tried using a dremel tool with a small router bit, but did not like the way it cut diagonal to the grain.

    I attached a picture of the repair using hide glue and putting the piece back as it broke off, but the glue line is visible and distracting. Is there a better less visible way to do this repair?
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	topRepair - 1.jpg 
Views:	182 
Size:	923.5 KB 
ID:	184822  
    Thanks a lot
    Bob Schmidt

  2. #2
    Registered User sunburst's Avatar
    Join Date
    Nov 2003
    Location
    Kentucky
    Posts
    14,725

    Default Re: new top F hole repair

    Quote Originally Posted by irishmando View Post
    Is there a better type of saw or a better blade to use for cutting the f holes[?]
    I use a jeweler's saw, but there are many good ways to cut them. A pin router is best, IMO, but you have to have one (I don't, that's why I use a jeweler's saw). It takes a deep saw frame to cut f-holes, but the courser teeth of coping saw blades makes the job difficult, as you've discovered.

    Quote Originally Posted by irishmando View Post
    Is there a better less visible way to do this repair?
    There is no more invisible (less visible?) method than hot hide glue and a good fit. The part about a 'good fit' is the important part.
    At this point, you have unfortunately used up your one chance at a virtually invisible repair and it's probably best left as is now.

  3. The following members say thank you to sunburst for this post:


  4. #3
    Registered User
    Join Date
    Oct 2007
    Location
    Davison Mich.
    Posts
    451

    Default Re: new top F hole repair

    a friend who has helped me with learning to build, told me once, that when you are done with something many, many times, you will put your hands on your hips, back up, and say, now how am I going to fix that. He has made 756 mands and a slew of guitars, and tole me it never stops, and you become a repair man by proxy

  5. The following members say thank you to Martian for this post:


  6. #4
    Registered User
    Join Date
    Oct 2015
    Location
    Howell, NJ
    Posts
    133

    Default Re: new top F hole repair

    Thanks John, Martain,

    Since this was my first attempt at cutting F holes I expected some issues although not this drastic. This makes the top a good candidate for a sunburst finish, but it is going on a quilted maple body so that won't work. I may think about starting another one and use this on a different body that I can sunburst.

    I am curious about the good fit. I assumed that gluing it up without disturbing the break would give me the best fit. Would it have been better to clean and flatten both edges?

    THanks for the jewelers saw suggestion. I will look into that.
    Thanks a lot
    Bob Schmidt

  7. #5

    Default Re: new top F hole repair

    Irish, cutting something fragile (or is weak along the grain - like wood!) is helped by backing it up with something else and cutting both. Very fine saw blades can be had from modeling supply shops, and if you need to use a coping saw for the throat depth, you can extend a shorter blade with a piece of wire. There are also fine blades that cut in all directions (spiral teeth) which can give better access because you don’t need to rotate the saw frame. (My jeweler’s saw doesn’t allow the blade to rotate like a coping saw usually does.) Also make yourself a block jig with a V cutout that you can hold in a vise (horizontally). Useful to support lots of thin things for cutting.
    By the way, years ago when Dremel discontinued the 1” diameter steel saw blades, I guess for liability reasons, a professional ship modeler I knew was upset, so I sourced some (much better quality) blades from the machine tool supply house. Still, I could see where one of these in a hand-held Dremel running 20krpm could give you a very nasty cut before you even noticed.

  8. The following members say thank you to Richard500 for this post:


  9. #6
    Registered User
    Join Date
    Sep 2002
    Location
    Colorado
    Posts
    4,206

    Default Re: new top F hole repair

    This is the method I came up with using a dremel drill press and an elevated platform with a pin under the cutter. Had the plexi template already.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	f holes-1.jpg 
Views:	118 
Size:	35.0 KB 
ID:	184825   Click image for larger version. 

Name:	f-holes-2.jpg 
Views:	90 
Size:	21.3 KB 
ID:	184826   Click image for larger version. 

Name:	f-holes-3.jpg 
Views:	90 
Size:	44.1 KB 
ID:	184827  


  10. The Following 2 Users Say Thank You to Jim Hilburn For This Useful Post:


  11. #7
    Registered User Walt's Avatar
    Join Date
    Sep 2002
    Location
    West Monroe, LA
    Posts
    367

    Default Re: new top F hole repair

    Quote Originally Posted by irishmando View Post
    This makes the top a good candidate for a sunburst finish, but it is going on a quilted maple body so that won't work. I may think about starting another one and use this on a different body that I can sunburst.
    I don't know, sunbursts go pretty well with quilted maple...
    Click image for larger version. 

Name:	quilt.jpg 
Views:	34 
Size:	290.8 KB 
ID:	184828

  12. The following members say thank you to Walt for this post:


  13. #8
    Registered User sunburst's Avatar
    Join Date
    Nov 2003
    Location
    Kentucky
    Posts
    14,725

    Default Re: new top F hole repair

    Quote Originally Posted by irishmando View Post
    I assumed that gluing it up without disturbing the break would give me the best fit. Would it have been better to clean and flatten both edges?
    Gluing the freshly split surfaces is the best procedure, but some form of clamping might have improved the joint and the look. That can be as simple as a piece of masking tape stretched tight around the split piece, a wedge pushed into the f-hole, or just about any improvised method of maintaining some pressure on the joint to keep things aligned and tight while the glue is drying.

  14. The following members say thank you to sunburst for this post:


  15. #9
    Adrian Minarovic
    Join Date
    Oct 2003
    Location
    Banska Bystrica, Slovakia, Europe
    Posts
    2,702

    Default Re: new top F hole repair

    Quote Originally Posted by sunburst View Post
    Gluing the freshly split surfaces is the best procedure, but some form of clamping might have improved the joint and the look. That can be as simple as a piece of masking tape stretched tight around the split piece, a wedge pushed into the f-hole, or just about any improvised method of maintaining some pressure on the joint to keep things aligned and tight while the glue is drying.
    Often just holding them tight while counting to 40 is enough for full strength HHG to grab. Then just lean it against a wall so there is no unnecessary stress in the break and let dry overnight.
    If you are brave enough you may open the crack and try again. If you apply wet piece (not dripping wet) of thick cotton string right along the glue line and wrap it with plastic foil (so it won't dry out), preferrably do the same on the other side as well. Leave it for couple hours and the glue should release. rinse with clean water and let dry before next attempt. If there is enough of clean hide glue inside the break (thus visible glue line, unless the visibility is from dirt) you can just re-heat the glue in place (hot gun or similar heat source, alcohol lamp...) and clamp it.
    From my experience, spruce doesn't want to get cut smoothlybecause of the summer growth that is much hahrder than early growth. FIne blades may seem to stop cutting as you lean against the dark line and rough blades want to chip out or cut "steps" at the grainlines. You need to cut well inside your lines and finish with sharp knife or files (sanding sticks).
    Adrian

  16. The following members say thank you to HoGo for this post:


  17. #10
    Registered User
    Join Date
    Oct 2015
    Location
    Howell, NJ
    Posts
    133

    Default Re: new top F hole repair

    Wow it looks like I should have asked some questions before I started.

    Matt,
    That sunburst is beautiful.

    Jim,
    That looks like a good way to cut them, but I don't have a dremel press so I want to learn how to cut them by hand.

    Richard, John,
    My jewelers saw does not allow blade rotation either. The blades I have are for inlay work so they are too fine. What size blades do you use?
    The coping saw is conveinent because you can rotate the blade but I have not been able to find blades that are fine enough.
    A V block sounds like a good idea to stabilize the work. I will give that a try the next time.

    Adrian, John,
    Thanks for the tips on how to do the repair. I may try to take it apart and do it again. After all, what could go wrong.
    Thanks a lot
    Bob Schmidt

  18. #11
    Registered User sunburst's Avatar
    Join Date
    Nov 2003
    Location
    Kentucky
    Posts
    14,725

    Default Re: new top F hole repair

    Quote Originally Posted by irishmando View Post
    The blades I have are for inlay work so they are too fine. What size blades do you use?
    I'm not completely sure what size I use, but nearly any size would work. IIRC, I use either 3/0 or 4/0 for general pearl work and they would be fine for cutting f-holes, but I have some larger blades that I don't like for cutting pearl so I use them for other things (like f-holes) I think they are 1/0.
    If you get a deep saw frame, one that looks sort of like this, you don't need to rotate the blade.
    Click image for larger version. 

Name:	Screen Shot 2020-04-07 at 11.21.59 PM.png 
Views:	16 
Size:	102.8 KB 
ID:	184834

  19. The following members say thank you to sunburst for this post:


  20. #12
    Registered User
    Join Date
    Oct 2015
    Location
    Howell, NJ
    Posts
    133

    Default Re: new top F hole repair

    Thanks John it looks like it is time for a web search.
    Thanks a lot
    Bob Schmidt

  21. #13
    Registered User Steve Sorensen's Avatar
    Join Date
    Sep 2009
    Location
    Santa Clarita, CA
    Posts
    2,315

    Default Re: new top F hole repair

    For my first builds, I would cut a line with the coping saw from one hole to the other down the center of the future f-hole, then carve out all the rest with a brand new x-acto blade . . . getting ever more careful as I approached the line. That way I had time to get a feel for the wood, get myself cutting cleanly across the grain lines and not have a force that could make a mess in the mix.

    Still, the final bit of cleanup was (and still is) always finished using custom sanding sticks made from dowels and the free paint stirrers from Home Depot.

    If you have the inner fortitude, throw this top out and start fresh. Sometimes, the only way to get a mistake right is to do it again.

    Steve

  22. The Following 2 Users Say Thank You to Steve Sorensen For This Useful Post:


  23. #14
    Registered User
    Join Date
    Sep 2002
    Location
    Colorado
    Posts
    4,206

    Default Re: new top F hole repair

    I think I remember Will Kimble say he cut his with a razor knife.

  24. The following members say thank you to Jim Hilburn for this post:


  25. #15
    Registered User
    Join Date
    Oct 2015
    Location
    Howell, NJ
    Posts
    133

    Default Re: new top F hole repair

    Steve,
    That is another approach I would not have thought of.
    If I can't make the repair completely invisable I will be getting another piece of wood and starting over for this build. I will pick up a cheaper back and side set and put this top on it and use it to try sunbursting the finish. This is all a learning process and I am sure there will be many more bumps in the road. I am planing an F5 and an A5 build also so I will be able to put these suggestions to good use, and probably have many more questions.

    Thanks as always for the invaluable help from everyone. This community is truely unique for its willingness to share expertise.
    Thanks a lot
    Bob Schmidt

  26. #16
    Registered User
    Join Date
    Sep 2002
    Location
    Colorado
    Posts
    4,206

    Default Re: new top F hole repair

    Watch some videos of violin guys knife cutting them.

  27. The following members say thank you to Jim Hilburn for this post:


  28. #17
    Registered User Steve Sorensen's Avatar
    Join Date
    Sep 2009
    Location
    Santa Clarita, CA
    Posts
    2,315

    Default Re: new top F hole repair

    I think that perhaps the most important skill to learn in building is to not saddle yourself with incremental fixing in the early stages of the parts-making process.

    It is incredibly important to know that the final instrument is the sum of your mistakes and, at the carving stage, the easiest way to increase the quality of your future instrument is to start again and do it right. Don't dwell on the mistake with forced compromises. Start over and do it better.

    Click image for larger version. 

Name:	QC Dept.jpg 
Views:	27 
Size:	300.5 KB 
ID:	184839

    PS - I owe a huge debt to James Condino for planting this idea in my range of possibilities when I was getting started. Probably the most important skill that I have learned.

    Steve

  29. The Following 2 Users Say Thank You to Steve Sorensen For This Useful Post:


  30. #18
    Registered User sunburst's Avatar
    Join Date
    Nov 2003
    Location
    Kentucky
    Posts
    14,725

    Default Re: new top F hole repair

    Quote Originally Posted by Steve Sorensen View Post
    ...the easiest way to increase the quality of your future instrument is to start again and do it right. Don't dwell on the mistake with forced compromises. Start over and do it better...
    Sorry, but I disagree. Not only is a starting over whenever things go wrong a waste of scarce materials, but it can be a serious waste of time and effort. My philosophy is more in line with 'fix it and move on'. Seldom have my mistakes been so bad as to have to abandon the piece. Never has the piece been perfect. An excellent repair is fine with me and I've learned from them all.
    When I can complete an instrument with no mistakes I'll be in another dimension. While I'm on Earth I'll make mistakes and fix them as I go.

  31. The Following 3 Users Say Thank You to sunburst For This Useful Post:


  32. #19
    Registered User
    Join Date
    Aug 2018
    Posts
    24
    Blog Entries
    1

    Default Re: new top F hole repair

    I'm building my first F5 after building two A4s. At least use this top to practice carving the scroll and binding channel, which I found to be very difficult. I'm glad I don't have to feed my family by carving scrolls! My F5 will have numerous minor mistakes but no one at the jam will even notice. If they do, I'll call it shop worn

  33. The following members say thank you to SBJ for this post:


  34. #20

    Default Re: new top F hole repair

    https://www.boscoviolinsupply.com/ca/3844/
    I use a violin f hole cutter to start and expand it with a small oscillating sander.

  35. The following members say thank you to riverview for this post:


  36. #21
    Adrian Minarovic
    Join Date
    Oct 2003
    Location
    Banska Bystrica, Slovakia, Europe
    Posts
    2,702

    Default Re: new top F hole repair

    I would strongly recommend not to waste the material and effort. For a beginner mistakes are inevitable and this is one of the smallest. Tiny non-structural crack is nothing compared to some of the bigger mistakes that WILL come. I would write few pages about my mistakes I've done (in mandolin building, I mean) and how I repaired them. Some more, some less succesfully in the first builds. But as I progress I get better at repairing my mistakes, sometimes I have hard times finding them after repair. But when I look at my #1, I see half dozen of them immediately half dozen after closer look and yet another half dozen I already forgot I did or are in places hidden from sight...
    If you toss the wood and get another nice piece of wood, you'll do another mistake sooner or later... that way you would never finish an instrument. Just call it good enough or try to fix it better if you dare, but don't throw it away.
    I would always tell beginner to use inexpensive wood (there are really decent pieces of wood at lumber yards or among firewood) and make sure the structural parts of build are best they can do, rest is cosmetics.
    Good luck!
    Adrian

  37. The following members say thank you to HoGo for this post:


  38. #22
    Teacher, luthier
    Join Date
    Oct 2017
    Location
    Southeast Tennessee
    Posts
    1,863

    Default Re: new top F hole repair

    This is out of my territory, but violin makers still often use knives. Very sharp knives with a very steady hand.

    Look at the current thread on "Iwamoto F5 mandolin #118 in progress," and you will see pictures of f holes started by drilling 3 holes in the top.
    Perhaps Mike will edit this with a link to that thread.

    If it were me, I'd scrape the crack repair level, reinforce it from the back with a sliver of spruce, and use it on this or another project.

    You're going to make mistakes. I have heard from a fellow who worked for a premium manufacturer [not Gibson] that sins were sometimes hidden during the construction process. We can't all be Stradivari. He would sometimes break parts if he was unhappy with them and throw them in the corner.

    For some reason, I keep a guitar bridge with a wing that I worked too thin in a junk box. Why I keep it, I don't know. It does come in handy as a drilling jig. It's not any good for anything else. I should probably just saw it up for ebony nuts and violin saddles.

    I otherwise defer to the experienced builders-- my background is repair and restoration.

    Try some of their suggestions. Get some different tools and experiment on a piece of scrap. With a little practice, you will find what works best for you.
    Last edited by rcc56; Apr-10-2020 at 12:24am.

  39. The following members say thank you to rcc56 for this post:


  40. #23
    Registered User
    Join Date
    May 2013
    Location
    MountainView, AR
    Posts
    317

    Default Re: new top F hole repair

    Up until now I’ve always did the F holes with a coping saw. This time I decided to get the plate closer to graduation measurements and use the Xacto method described above and I’m pretty pleased with the results. I just drilled (undersized) holes on each end of the F hole with forstener bits (drilling half way through on one side, turn plate over, and finish drilling hole so as to minimize/prevent tearout) and carefully cut with a sharp xacto. Again cutting half way through, turn piece over and finish cutting. The F-hole pencil markings must be in the same location on both sides of the plate or at least very close. Clean up will be done with sanding of course.
    I’m laid off from work for now due to the COVID-19 so I’m building a mandolin to occupy my time lol
    Click image for larger version. 

Name:	6F6F5ED6-28A9-4281-906F-E3B3EE2C07B9.jpg 
Views:	31 
Size:	910.4 KB 
ID:	184878

  41. The Following 2 Users Say Thank You to Clinton Johnson For This Useful Post:


  42. #24
    Registered User Drew Streip's Avatar
    Join Date
    Jan 2016
    Location
    Chattanooga, TN
    Posts
    426
    Blog Entries
    2

    Default Re: new top F hole repair

    Quote Originally Posted by sunburst View Post
    Sorry, but I disagree. Not only is a starting over whenever things go wrong a waste of scarce materials, but it can be a serious waste of time and effort. My philosophy is more in line with 'fix it and move on'. Seldom have my mistakes been so bad as to have to abandon the piece. Never has the piece been perfect. An excellent repair is fine with me and I've learned from them all.
    When I can complete an instrument with no mistakes I'll be in another dimension. While I'm on Earth I'll make mistakes and fix them as I go.
    Iím with John... Iíll be maybe the first in this thread to say that the existing repair doesnít even look that bad. Sure, itís not completely invisible, but if you had finished the instrument and asked me to find the repair, Iíd probably be hard-pressed to identify it.

  43. The following members say thank you to Drew Streip for this post:


  44. #25
    Adrian Minarovic
    Join Date
    Oct 2003
    Location
    Banska Bystrica, Slovakia, Europe
    Posts
    2,702

    Default Re: new top F hole repair

    Quote Originally Posted by rcc56 View Post
    We can't all be Stradivari. He would sometimes break parts if he was unhappy with them and throw them in the corner.
    There is more than few Stradivari violins with knots, pitch pockets or other defects in tops or backs. They get rarely pictured or showcased so the "mystery" of perfect Strad won't be damaged on public... some folks have millions in it.
    Adrian

  45. The Following 2 Users Say Thank You to HoGo For This Useful Post:


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •