1978 Besson New Standard -- Valve Guide Wear / Noise

[tampaworth]

http://www.ebay.com/itm/NYLON-SCREW-...item519b71f50b

The original hex head they come with is quite wide and tall in profile once screwed in so there is plenty of material topside to work with. The screw has securely threaded into both my English and American euph and baritone respectively. Not sure about application for your Buescher re: thread size but as Daniel has noted precision threading may not be required as it seems to tap into both American and metric.

[ghmerrill]

Thanks. I take it that's for $2.30 PER SCREW. So over $9.00 for a set of 4 plus shipping. I'll keep that as a backup, but may run five miles down the road to Fastenal and see what they have on hand or can get me cheaply. One candidate is

http://www.fastenal.com/web/products/details/0182432

This is the correct thread size for the Buescher. But I don't know what the head looks like. If it's square or pan head, that would be great. If it's round head, not so great.

But thanks for pointing me again to Ebay (which I often forget as a source). This looks like it might be ideal for me, and I get 100 for a little over $7.00 including shipping. I could repackage them in a set of 4 and resell them at a huge profit to old tuba and euphonium owners (or at least to owners of old tubas and euphoniums). This could be the ticket to my life of leisure in retirement.

http://www.ebay.com/itm/3-48-x-1-8-N...item5adb994c01

Or these for at $10.85 for 100 with free shipping:

http://www.ebay.com/itm/Nylon-6-6-Ma...item3f23c0129e

[daniel76309]

I recognized that the screws were "overpriced" for what they are, but at the time thought they were a "specialized" kind of thing, i.e. designed for this specific use for musical instruments. But after using them, I would have to agree that any nylon screw that fits the hole--or even "kind of" fits the hole, would probably work just as well. I think you are on to something. You might be better off with a hex head screw rather than a slotted screw if you can find one, but on the other hand, by the time you file it down there may not be much slot left anyway. Let us know how it works out.

[ghmerrill]

I ordered the fillister head screws today -- mostly because I believe they provide a thicker head. I agree that very likely by the time they are filed down, the slot will have disappeared. I will report on the results.

[coolguy684]

they cant be too long though, wont they block the vent column in the hollow piston? I would cut them down to the same length as the original brass ones. But yes, i probably should not have bought $50 worth. Oh well.

[ghmerrill]

Length is not too much of a consideration at the point that they screw in. But yes, I do intend to cut them down. I could have bought 1/8" versions, but I'd rather have ones I can cut down and possibly use for other applications. Cutting down a nylon screw requires only a razor blade or Xacto knife.

[ghmerrill]

Picked up my horn yesterday after two weeks of waiting and the valve guide tacquet replacement work wasn't done yet --- so I took my horn back home and did it myself with the guides I had purchased, needle nose pliers, a new sharp box cutter blade heated in a candle (to size them laterally), and (OK this is the weird part) a rotating foot grinding stone from a pedicure set to thin the height of the guides (very carefully), and a file to finish it all off nice and smooth! If anyone has a horn like mine and wondered -- should I do it? DO IT! The difference is like night and day. Smooth action and QUIET -- should have done it way sooner!

This is great. I wonder if you could provide a bit more detail in terms of the procedure. For example, did you do the cutting/trimming/filing with the guide screwed into the piston? And if so, how did you guard against damaging the piston? How did you get the alignment correct and with the right degree of tightness when the guide was screwed in? Did you mark and trim, or just use repeated trial and error?

[daniel76309]

I gather that you are a handy guy and may come up with something better, but I can tell you what I did...

I don't think you can cut the screw before placing it or there wouldn't be enough bulk of material on the screw head to provide enough strength, i.e. there is a fair amount of resistance going into the hole. (Which is good in that they won't spin or come out, but is bad in that removing them for replacement will probably require drilling them out.)

So after placing them, I filed the top down using wet/dry sandpaper I had glued to a paint stick (220, then 320). If you have an "emory board" it would accomplish the same thing. I put the stick down on a flat surface and moved the valve along it--I think that makes for better control. At least for my horn I had to file away most of the screw head to fit the slot. Then I just used an exacto blade to cut the sides (no heat). I don't know of an "exact" way to assure that you are taking off evenly from both sides, but at least on my horn, it was about even with the main shaft of the screw, so I used that as a guide, i.e. what you end up with would be three millimeters wide. There is a little rotational "play" in the piston, but there was with the brass guides too, so I don't think I changed anything. Viewing the valve port through the one accessible hole (#1 on the compensating side), it doesn't seem to be critical, i.e. the amount of movement doesn't seem to result in any visible blockage of the air pathway.

[ghmerrill]

I gather that you are a handy guy and may come up with something better, but I can tell you what I did...

That all makes sense. I expect that I should be able to thread the screws I'm getting in and out since they will have an exact thread match. Also, I have a tool that I got from Ferree's (G39 Valve Guide Fitting Tool) which is "scientifically shaped, drilled and tapped to hold valve guides and stars for valve instruments." Scientifically, no less. It's tapped for the 3-48 threads that most American instruments use. Basically, the scientifically shaped tool is a piece of steel with a 3-48 threaded hole in it that you can use by clamping in a vise "and eliminates filing of the valve". Of course, you have to be sure you're cutting/filing the guide at the correct orientation.

I have yet to use it, and got it for use with the brass guides (which require more work than the plastic ones). But I'll try it with the plastic ones as well.

[tampaworth]

ghmerrill and daniel76309 both seem to have improved on my previously posted improvised technique involving the rotating pedicure stone and the candle heated box-cutter No tips to really add. In retrospect I like daniels technique of keeping the abrasive stationary and moving the valve over it to reduce the height. Also I like the idea of trimming it with an Xacto after the height reduction, easier to trim and eliminating the need for heat. Nice with lots for all to learn. Good luck with the mod!

[coolguy684]

The xacto can shave strips of the nylon. I found that to be much faster than the fine sandpaper I had.

[ghmerrill]

Here is a brief but accurate description of how to use the "scientifically shaped" valve guide fitting tool: http://www.thebandroom.biz/01_item_a...ms.php?id=1580.

[zp6827]

I also have a 1978 New Standard, and upon visiting my local technician, he advised against it referencing the durability of brass vs nylon. I want to do it, but I was wondering if there is any negative side with nylon vs brass.

[coolguy684]

Brass is fine but they have to fit real well or there will be annoying noise. Also once a year I'd unscrew and screw the brass guides out so that corrosion doesn't build up as much. Also don't wait till they get real worn to replace them. Otherwise, you won't be able to grip them easily with pliars without scratching that piston.

[ghmerrill]

You're running into what I regard as more of an ideological issue here than a practical one. There are two factions regarding valve guide material: the brass faction and the plastic faction. (This is similar to the factions regarding lanolin or not-lanolin as slide lube.)

The brass faction tends towards several different beliefs concerning brass as the best material, some of which are definitely true. Brass guides are more durable and won't need to be replaced very frequently at all. A well-fitted brass guide should not be noisy, though over some time a bit of noise can be expected to develop. Moreover, however, they also seem to believe that since brass was the original material used, then any replacement should be of the same material. This is much more open to question.

The plastic faction sees that the plastic guides are much easier to fit and install, and that they result in zero guide noise. But it must be conceded that they wear much more readily than brass and that you can anticipate replacing them on a regular basis.

The negative side of nylon as compared to brass is the comparatively frequent replacement necessary (and associated expense if you don't do it yourself). Brass guides should very likely last decades. I think my 89-year old tuba has the original ones, and they still work fine, but are a bit sloppy and noisy. I intend to replace them with plastic and see how that goes. I wouldn't be shocked to discover that I need to replace plastic ones on an annual basis, but I don't know. However, once you get the skill (and materials) to do that, it's pretty much like cleaning your instrument or lubing slides.

It looks as though the going rate for valve guide replacement on a tuba or euphonium is $15 per valve. So $45 for three valves or $60 for four. I believe this is independent of the material used. I don't think I'd want to pay that (like I don't want to pay someone $10/valve to replace the felts and corks). But if the plastic ones last a year or two, I suppose even that isn't totally unreasonable; and the longer they last, the more reasonable it is.