Al Dzina

Members
  • Content Count

    48
  • Joined

  • Last visited

About Al Dzina

  • Rank
    Junior Member
  1. Jeffrey; Sorry I got your name wrong, my fingers were so mixed up in learning of Michael's choice of Super-glue. But at any rate you knew who I was talking about. Al;
  2. Hello Michael; I can not believe my eyes, that you are suggesting super-glue to be used on a string instrument. Did you clear this with Jeffery? I can see by your last post that you are sticking your head into the sand, it should stay there till you start using Titebond Glue.
  3. Alan; I have to disagree with your theory that there are no permanent joints. The following I would consider as permanent repairs: 1. Any graft. 2. Glueing a beg box back on the neck. 3. A break in the middle of the neck. 4. Replacing a heel on a neck. 5. Crack on top or back plate. Any of the above I would not glue with a NON permanent type of glue, like hide glue. These joints should be brought back to virgin wood integrity as close as possible. I'm with you in regards to double the price of any instrument that has had permanent glue used where temp. (hide glue) should always be used.
  4. Terry; I understand your frustration with the types of glue. Any part that will ever have to be removed for repair or replacement should be glued with hide glue. Liquid hide glue made by Franklin Co. is as strong and reversible as hot hide glue. I only suggest using Titebond III on grafts, cracks and dowel type permanent repairs. Titebond III is not reversible, but Titebond II and Original are both reversible, but I would not use them where one would assemble a violin in the first place (including fingerboards.) Basicly use hide glue on temporary joints, and Titebond III on permanent joints. I hope this clears up the glue mess. If you are so inclined to use hide glue on permanent cracks or grafts, be prepared to redue it at a later date.
  5. I have never worked with heat treated bridges. But I have made bridges from a very large list of woods and other materials. Of all the various materials used the one that had the most notable effect on tone was a material called Micarta a linen/resin very hard material. The only one that came close was aluminum. This info is for what its worth. Also I had better results with vertical grained orietation then with horizontal grain. There was no difference in tone, but less warping or bending of the bridge. Al;
  6. Re: gmhg41: I would suggest using Titebond II on any areas that are not normally held together with hide glue. Titebond II is stronger then hide glue and is reversible. Do not use Titebond III it is not reversible like II. If you ever wide up with a broken neck then you can use III, but no screws, just use dowel pins. Al;
  7. Re: b Sharp, HongDa & All; For a second I thought that violins would never have been invented if not for hide glue. Hello fish glue, but does it creep?
  8. Hi: GlennYorkPa; I think you are correct that Titebond I and "Professional Titebond, Original Wood Glue" are one and the same. Franklin Glue Co. indicates that II is moisture proof, and III is water proof. They also say that III is the strongest of their products. As you can see all of my tests were done with II, since III came out I have used nothing but. Not having ever tried what you call "reversible", I can only assume that II would be reversibile and III is not. Thanks for your opening comments. I hope the above info. is helpful. Al Dzina
  9. [Re: Cello broken neck] [Re: Jeffrey & Dick] My intent was and is not to start a conflict. I’m sorry if you take the negative position in this matter. I may at times become very involved and emotional when I see that there are still repair shops out there repairing string instruments with screws. Now if an amateur is using screws this is forgivable because of lack of experience. But when an associate of a Fine Violin Repair Shop is using screws I become very upset. I’m happy that you are glad that the dowel system works for me. But believe me it will work for you or anyone else as well. You are correct that temp. & humidity goes hand in hand when dealing with expansion and contraction of wood. Humidity is a very small factor even in wood, unless you are located in the Mississippi Valley Delta, then you call it “moisture”. It has no effect on metal that is why I did not address it in my studies. You are very incorrect in your assumption that I am not familiar with the mix of wood and metal. When I first got started in the repair of string instruments screws were indeed used. But after seeing failure after failure I looked into the reason and found out that screws or threaded fasteners of any type work loose after a period of time. That’s when dowel pins came to the fore. In the last 10 years we have saved all the failed screw jobs and some day hope to put them in frames. These are not screws that we have used; these were used by other repair people in the general area. I have not used metal fasteners in 58 years. As far as conflict of interest goes my comment was that it “looks like a conflict” because you and Dick both worked for Shar a Fine Instrument shop that would allow screws to be used on fine instruments, you must agree that the association speaks for itself. Dick my only comment to you is that I’m sorry that you took my innuendo to heart. You indicate that your integrity was maligned by my comments, in essence you maligned your integrity by yourself when you told “skreechee” to use a screw to repair his cello. In the last 58 years I have seen hundreds of screw jobs on string instruments. I would without any reservation estimate that more than 95% had failed in one way or another. I’m not saying that the dowel system is perfect, but since I have employed dowels I have seen less then 5% failures. But believe me they are a lot easier to rework. When you run across a job that was done by a bolt, and then by the addition of a screw next to the bolt it really becomes a task to first remove the bondo or epoxy and then back out the bolt and screw, then plug the holes with dowels, so that a new dowel can do the job right. If you have never had this experience you don’t what you are missing. I really do not wish it on anyone. I have seen a string bass neck that was repaired by 3 metallic fasteners, a bolt with a nut, a lag bolt and about a 3” wood screw. I can only assume that the butcher that did this job felt that if one screw did not hold you might as well add a few more. The three screws did not do the job. I removed the three screws plugged all holes with dowels, and then installed one ½” dowel, and have had no problems to date. This job was done about seven years ago, I have photos to verify this mess. I may be on a one man mission to remove metallic fasteners from use on string instruments. It is clear to me that you would only use screws on cheap instruments. I refuse to use screws even on a cigar box fiddle or an orange crate cello. I have used the dowel system on cheap and very expensive instruments as well. If the job is done right you may not even tell how it was done. When I say done right that means removing the fingerboard on expensive instruments. I shall close hoping that along the way I may have picked up some help.
  10. Hi Picknbow; The expansion numbers are based on temperature only. Temp. is by and large the greatest factor in "metal-wood" faliures. Moisture could be a factor, but most of the time we are only looking at low levels of humidity. I can only hope that most luthier shops have some control over the humidity problem. As far as your choice of epoxy to keep moisture out do not forget that epoxy has a different rate of expansion. I have no idea what that factor is, because I never us epoxy on that type of repair. The reason being that if another break happens in that area epoxy is hard or impossible to remove.
  11. [Manfio, Matt] I submit the following test that I did on Titebond II back in 2002. You will have to trust me, I do not work for the Franklin Glue Co. This test was done on my own to prove to me that creep does not happen. The two test samples are still under pressure at this date, with no sign of any creep whatsosever. Please see my thread about Cello Neck Repair. WHAT TYPE OF GLUE? Throughout history there has always been a debate or discussion about which is the correct glue to use in making or repairing string instruments? It goes without saying that hot hide glue is the best for the assembly of string instruments. Hide glue not only has the strength required to hold a violin or a string bass together, but also has an attribute that allows parts to be removed, as repairs are needed. Due to the fact that hide glue has the ability to let go at will, has always indicated to me that it is more or less a temporary versus a permanent type of adhesive. I realize that with hide glue you have the ability to control strength through mix but you still have glue that is affected by moisture. I feel that a crack or repair that is to be permanent should have glue that fits that requirement. My choice is Titebond II because it is strong, permanent and moisture proof. I know this will open a can of worms because some people feel that Titebond II creeps after a period time. I want to make it clear at this time that I do not work for the Franklin Glue Co. nor do I own stock in the company. I have been using Titebond II since it was introduced and have never had a failure or any indication of creep. Being concerned about creep, I called Franklin International to find out how much and over what period of time this creep was evident. Franklin technical support had heard about creep but had no first hand information nor had done a study in regards to it. So I decided to do my own study on the subject of creep. I decided to run two tests as described below, see Test Fixture No. 1 The Test Sample is composed of two pieces of hard maple .75”x1.5”x4” long, the glued area is 1.5”x1.5” and Titebond II was used. The test sample was made up and clamped on 4/30/02, after approximately 24 hours of cure time the sample was placed in Test Fixture No. 1 with the spring tension set at 30 lbs. I was not sure that creep would not be present so the tension was set low. On 5/31/02 the tension was increased to 40 lbs. due to the fact that there was no indication of creeping visible. On 7/17/02 the tension was increased to 45 lbs. As of the date of this article there has been zero slippage indicated, the dimension at “A” has remained exactly at 2.47”. I am aware that this is not the most scientific test possible, but I feel that what was attempted does indicate that there is no slippage at all. For the scientific community we shall add the following test parameters. The room temperature varied between 55 to 74 degrees F., and the humidity was between 35 to 55 percent. Now to move on to the second test, see Test Fixture No. 2 This time the Test Sample is an old ¾ Cello neck, which lost its peg box. The heel was mounted in a vise and a mallet blow was applied to create a fracture near the center of the neck. The fracture was first glued with Titebond II, and then a 3/8” slot by 4” long was routed in the center of the neck 2” above and below the fracture. Then a hard maple insert was fitted with Titebond II. After the maple insert was trimmed down the cello neck was mounted on to a piece of 2”x6” and the aluminum angles fitted. The spring and chain were then put in place and set to 25 lbs. tension on 5/25/02. On 6/27/02 the tension was increased to 35 lbs, still no detection of creep. On 7/12/02 the tension was moved up to 45 lbs. and has been there ever since, without any signs of creep or separation. Also note that no fingerboard was glued to the face of the neck. The fingerboard as a laminate would add a great deal of strength to the test, and that’s the reason for leaving it off. Also want to comment that the flat surface of the neck has less then .001” gap at the center point. These two tests indicate that creeping is nonexistent. The two samples shall stay under tension as far as I’m concerned forever. I have repaired many instruments using the above system and have never had a failure. If ever or when the samples fail I shall be ready to make a report as to when it took place. In conclusion I would like to add the following. We must remember that 400 years ago the instrument makers had only hide glue available to them. Today some feel, because of tradition, that hide glue is the one and only glue to be used on a string instrument. We should be thankful that today there are available may types of adhesives that all have a different function. I shall repeat that hide glue is very useful because it can be mixed in various strengths. Its possible to open an instrument that was assembled with hide glue, but don’t try that with epoxy. I still feel that a permanent type of glue should be used on crack repairs, grafts and restoration. I prefer Titebond II or III. I'm sorry but I have not found a way to paste the pix of teat fixture #1 & #2.
  12. Re: Cello broken neck [Re: Dick Mattson, Jeffrey Holmes & Skreechee] I want to go on record and state that using a metallic fastener of any kind is not an acceptable method of repair on the string family of instruments. Later I shall attempt to explain why and show the correct way to make the above mentioned type of repair. First let me give you a brief bio in relation to string instrument making, restoration and appraising. I have been working as an independent repair shop for almost 60 years. My studies on violin making were done in Mittenwald, Germany. I also have a BS degree in Electrical Engineering, I realize that this is a non related field but the discipline is still very essential. Jeffery, I wish to take issue with you and David Burgess (playing around) with different methods of repair being described on less expensive cellos. You indicate the use of a wood screw was the most effective method of repair. I think, possibly what you meant to say was that it was a cheap and fast type of repair. You mention the drilling of the screw hole is stepped to allow compression at the joint. This procedure indicates to me that you are relying on the screw to hold the two parts together. Any repair of this type should not need to depend on compression of any kind. I have a felling that you were using hide glue, so the compression from the screw is very important, because hide glue is a temporary type of adhesive. The screw can still work loose as will be shown below. At this time I shall indicate how this type of repair should have been done. The area of the break is first glued with Titebond III and clamped (that’s all the compression required) until the glue has reached total strength usually twenty-four hours. At this point a 3/8” hole is drilled through the fingerboard (on less expensive instruments) and a maple dowel pin is inserted minus the thickness of the F/B, again using Titebond III glue. On an expensive instrument the F/B should be removed before drilling and installing the dowel pin. Compression is not required in order to maintain integrity at the break with this type of repair. I’m glad that you agree that wood and metal have vastly different rates of expansion and contraction. Let me explain how vast the expansion coefficient really is. If we look at the coefficient number only it is not very easy to relate it to the problem at hand. If we look at it as a percentage factor instead it relates as follows: Maple for a 3/8” dowel = .35% to .75% VS Iron for a 3/8” bolt = 5% to 10% As can be seen from the above the expansion for maple is very small compared to iron. On a 3/8” wood dowel to a 3/8” iron bolt has an expansion 13 times greater than maple. I realize that you are not using a 3/8”wood screw but the factors involved would still be fairly close. Jeffrey, you must remember that the small expansion of a maple dowel installed in a maple neck is very minor indeed. You must also realize that in this configuration (wood on wood) both elements expand at the same rate regardless of grain orientation (which is very small), and remember that compression is not required or needed with this type of repair. I have used this method of repair on very expensive and not so expensive instruments as well and monitored their condition for about 20 to 25 years with no ill affects at all, including total lack of creep. At the time these repairs were done I was not using Titebond III because it was not available yet. I just used Titebond I or II or whatever glue was readily at hand, without any failures at all. But I never used or use hide glue for permanent glue joints, likewise I always use permanent glue for center seams on front and backs of violins and do not have any creep problems at all. Just keep in mind that a mixture of wood and metal you will have 13 times the amount of expansion during any temperature changes. Also do not forget as this expansion is taking place, the force of the string tension and the vibrations of the bowed strings are working to loosen the metallic fastener. And this is all taking place regardless of how much compression you put on the break with your screw. Now here is something to think about. If you broke something made of metal would you use a piece of wood to repair it? Just think about it. Now Jeffrey I want to address the issue that you worked with Shar Fine Instruments for period of 17 years. I find it strange that Dick Mattson now works in the Shar Repair Shop. It almost, in a way, sounds like a conflict of interest of some sort. (Just a thought.) I could go on but I want to stay as close to political correctness as possible. My last comment is for Skreechee. His last input was “that he used the threaded screw as Jeffrey indicated and it is as tight as I am going to get it but it does not look pretty. I think it is one of those times when grafting should have been done etc. etc.” Then he goes on “I hope it does hold or I may be eating pegbox when I come to string it up! It is for learning on and I suppose it taught me something. Do it properly next time.” Skreechee you are so right do it properly the next time. But, do not use hot or cold hide glue, use Titebond III on all permanent glue joints, and no screws.
  13. Skreechee; NEVER,NEVER use metal fasteners of any kind. You must remember that metal expands at a different rate and will in time work loose. Use a good hard wood pin about 3/8" dia. Use Titebond lll glue it is very strong. In my 60 years of repairing instruments I have never seen a screw job that did not need to be redone. Metal fasteners will not work!!!
  14. Does anyone know when Machine Heads were first used on a cello? In ref. to Machine Heads I'm talking about the same system used on a String Bass.
  15. I addressed this post to Doug in error. It should be addressed to Brad Dorsey instead. Sorry for the error, but I do not understand the correct methode that allows me to respond to a specific thread. Thx for any help. Al Dzina;