Author Topic: Bridge Problem (Read 813 times)

mica · « **Reply #30 on:** October 05, 2009, 02:59:18 PM »

From the looks of the broken screws, they have actually been broken for some time - there's only a tiny bit of bright brass colored metal, the rest is well-oxidized. As you know we're not using the brass screws for many years now. I'll be happy to send you a set of the stainless screws (email me your shipping address, I already have them packed up for you).

But of course, you'll need to get those broken brass screws out. The reverse-thread screw is an excellent suggestion, but if it doesn't work, you'll need to drill out the screw, leaving a larger hole. It really doesn't matter since you'll have to fill the hole either way.

Once you fill the hole with a dowel and titebond wood glue, then drill a pilot hole for the stainless steel screws and replace the tailpiece.

I too am relieved that there wasn't more catastrophic damage. I'm also a little curious about the silicone, nobody here remembers using it in that location before. Learn some bit of Alembic trivia every day!

lembic76450 · « **Reply #31 on:** October 05, 2009, 03:46:17 PM »

Mica,

Are the stainless screws the same size as the brass screws? I guess what I am asking is if you replace the brass ones with stainless do you recommend plugging the original holes and redrilling for strength?
thanks
Kenn

dela217 · « **Reply #32 on:** October 05, 2009, 04:18:26 PM »

Harald - I had the same problem with one of my prior basses. The tailpiece failed in the same manner as yours did. I had to drill out the original screws and install stainless steel screws. I did have to do the dowel and Titebond glue trick as Mica described. I then replaced all the tailpiece screws on the rest of my old basses before this happened to me again!

Michael

tdukes · « **Reply #33 on:** October 05, 2009, 07:59:59 PM »

Should I be concerned about the screws holding the bridge on my 1977 6-string guitar? They appear to be brass as well. Has anyone had this kind of failure with a guitar, or is it just a problem for basses.

Todd.

harald_rost · « **Reply #34 on:** October 06, 2009, 12:16:35 AM »

Again Thanks to all for your comments and help and especially to Micah for great customer service (I sent you my shipping address via E-Mail for the screws).
Michael, good to see that I'm not the only one with this kind of problem. I was really shocked at the first moment. But if the damage was in the past before I bought the bass in 1999 it was not my fault that this happened. May be the seller didn't know that or didn't tell me that.
But to look forward, I will do the dowel and glue trick. I worked with wood in the past an this will not be a problem for me (I hope). I even found a distributor for Titebond here (never heard that brand before).

Harald

terryc · « **Reply #35 on:** October 06, 2009, 01:26:52 AM »

toma_hawk..I have performed removal of screws, broken bolts, inserts from wood to engine casings, if it set up securely, using a high quality hardened bit with a vari speed drill mounted in a vertical stand then it is easy.
If you wanted to 'over engineer' this problem then go down to you local fastener supplier and get threaded inserts and appropiate bolts but the dowel and glue is just as good.
Brass is only good for effect as it looks nice..not very good for loaded or stressed fixings.
keith h..yes i was..sorry for that.

jacko · « **Reply #36 on:** October 06, 2009, 04:24:52 AM »

terry, just veering slightly but I have to remove several sheared bolts from my MG bodyshell. Are you saying that the slower I run the drill the better? And what sort of speed do you recommend?

Back on track - good luck with the repair Harald

graeme

811952 · « **Reply #37 on:** October 06, 2009, 07:54:50 AM »

Easy outs, in my experience, work best with a very slow drill. Don't rush it, and if you're not certain about it don't be embarassed to take it to a machine shop to have that done. If you're replacing with identically-sized screws, you shouldn't need to modify the holes at all. If the screws are slightly smaller or threaded differently, my personal inclination would be to glue at toothpick-sized dowel in the side of the hole(s) and use the existing holes. That way the screws will still be into the hard neck woods and not into a softer dowel...

john

(Message edited by 811952 on October 06, 2009)

slawie · « **Reply #38 on:** October 07, 2009, 02:05:51 AM »

Engineering rule of thumb!

The smaller the drill bit the faster the speed

An easy out should only ever be used with a T wrench
or stock. Never ever use a drill.

Do not try to lubricate the screws to get them out you will only absorb the lubricant into the wood.
This could possibly stain the wood and most likely make it swell.
You can try some freeze spray to shrink the screw/wood interface slightly
just before using the easy-out.

slawie

bigredbass · « **Reply #39 on:** October 07, 2009, 10:06:21 PM »

Slawie nailed it: Any one familiar with the easy-outs would use the T-handle to back them out. And they'll back out fine. Mica does this for a living, folks: The glued hardwood dowels filling the holes after the screws back out will do the trick.

The older Alembics with the wodd beneath the tailpiece used VERY hard woods like ebony as spacers, not as coupling devices to the top.

I DEFINITELY would not fill the holes 'as is' and glue to the top!

terryc · « **Reply #40 on:** October 08, 2009, 07:26:38 AM »

jacko...on metal the drill should be considered like a lathe tool..run it slow and lube with emulsified oil to keep it cool(or any oil) but not spray lube like WD40 as it will evaporate with the heat.
I couldn't tell you how many revs/min but just enough to begin cutting into the bolt and producing swarf.
Drill a pilot hole with a smaller drill so the larger bit point will fit into the smaller hole and prevent run off.
Clamping/jigging everything tight is the key here so there is no movement whatsoever of the piece to be drilled and the mount the drill into a fixed stand.
Once it begins to run off it is a pain to correct.
Good luck with removal

terryc · « **Reply #41 on:** October 08, 2009, 07:33:21 AM »

jacko...on metal the drill should be considered like a lathe tool..run it slow and lube with emulsified oil to keep it cool(or any oil) but not spray lube like WD40 as it will evaporate with the heat.
I couldn't tell you how many revs/min but just enough to begin cutting into the bolt and producing swarf.
Drill a pilot hole with a smaller drill so the larger bit point will fit into the smaller hole and prevent run off.
Clamping/jigging everything tight is the key here so there is no movement whatsoever of the piece to be drilled and the mount the drill into a fixed stand.
Once it begins to run off it is a pain to correct.
Good luck with removal

jacko · « **Reply #42 on:** October 08, 2009, 07:47:44 AM »

Thanks for that Terry. Unfortunately the sheared bolts are in a position that means the drill will be hand held. I'll let you know ho I get on.

Graeme

811952 · « **Reply #43 on:** October 08, 2009, 10:52:50 AM »

I don't see why they would require hand-held. I would clamp it (on carpet with soft clamps) in the drill press to drill holes in what's left of the screws. A press is far more accurate and controllable than my hands, and is setup for the right spot before any drilling happens.

john

David Houck · « **Reply #44 on:** October 08, 2009, 11:19:40 AM »

John; Graeme is talking about his MG automobile, which might be a bit of a mess on the carpet.