Double Bass Tips for holding endpin in place

[PaulKing]

Experts - I've got two King Mortones that share the same problem. Endpin isn't quite good enough fit to hold completely fast.
It's minimal, like in years of playing they've shifted no more than a couple of mm. It's not like its gonna pull right out like an Exocet missile. I think. But two things do bother me:
1) the pin starts to angle forwards just a fraction, and I can feel a little sideways/back & forwards play when tension is released from strings.
2) one of them (which I admit is a stock bought replacement pin, that should fit - at least on paper...) starts to buzz sympathetically (mainly on open A, fwiw), which is a problem when it comes to recording. I have to release strings, jam the pin back in a mm or two, retension.

Are there tried and tested tricks that can help prevent the thing vibrating loose? I've tried little micro-shims of masking tape, black-tack...
Or is it finally time for a luthier to fit it properly?

Thanks in advance.

 

[PaulKing]

I just read Auspis' recent post on same issue.

Double Bass Thread 'DB - Endpin socket question'

Aug 5, 2025

Hello this morning I examined my grand-father's double bass, the end pin, and I notice that it's not parallel to the instrument it has an angle. Clearly the wood was repaired previously as you can see in the picture, using strong glue. There is a reinforcement plate inside, looks stock, it looks in good condition, not cracks can be seen from the interior of the instrument.

However, it looks like a metallic sleeve tube is missing around the end pin socket and the pin is prying towards the front of the instrument.. It's all very stable, nothing moves, but..

How bad is this in your...

• Auspis
• Replies: 19
• Forum: Setup & Repair [DB]

Yes I remember the sandpaper trick now. Will give it a try

 

[Don Hergert]

Just to be clear, are you talking about the endpin plug shifting forward inside the internal end block, or the endpin itself shifting forward inside the endpin plug???

They can be and often are two different issues.

 

[Steven Ayres]

The original endpins by HN White used a taper a little larger than the current standard, so replacements generally will need some attention to that. I can reproduce these endpins by copying from an original on the lathe. They're the same for Kay.

 

[KUNGfuSHERIFF]

Spend the money and have a nice Ulsa endpin and collar installed.

 

[eh_train]

The original endpins by HN White used a taper a little larger than the current standard .... They're the same for Kay.

Hi Steven,

Did you mean that White and Kay basses had the same endpin specs? Because, nope. I just replaced yet another original Kay endpin. They are nasty little things, about the diameter of a dime, steel on steel, and with no taper at all...

 

[Steven Ayres]

Did you mean that White and Kay basses had the same endpin specs?

I'm talking about the wood endpin sets that are common on earlier examples and optional well into the '50s. In the photo I have one from a '52 Kay C-1 on the left, that on right is from American Standard #1430. I've seen some variations, but this is the most common set, which came with both 3" and 6" tapered pins iiuc. These taper from 1.15" diameter at the body to 1.015" at the 2" mark.

 

[eh_train]

Interesting! The vast majority of Kays that I see have the all-metal endpin, below. I call it the "nasty, short, and brutish" model. Note the interior part of the collar - dime diameter, and no taper whatsoever...

 

[KUNGfuSHERIFF]

That’s not an endpin, it’s the murder weapon.

 

[PaulKing]

Ah this all makes sense, thanks Steve et al.
Its the collar that works loose ... like this:
1937


1961


Actually I can see that the block inside the '37 must be going out of line a bit, the ribs have sunk a little there. That's confounding the problem. But the plug is still slipping (and eventually buzzes).
Oo-err. Mind you it does seem stable, been like that for at least 10 years or something. Unless its getting worse and I just didn't notice?

The '61 ... well I just slacken the strings and tap it back in from time to time. I think there's already some sandpaper on that. Maybe it's the wrong way round (sand against block perhaps?).

I put a new pin on my '38 Kay too and that fits like a glove! Or maybe luthier Steve Laws did that ... I forget now, was so long ago.

 

[KUNGfuSHERIFF]

Is the bottom block still firmly attached to the ribs? Tap around the area with your knuckle.

 

[PaulKing]

Is the bottom block still firmly attached to the ribs? Tap around the area with your knuckle.

Hmm this might be an issue developing after all.
Tapping with my knuckle didn't reveal anything, but if I push firmly on the ribs with my finger around the bottom block I hear that creaky squeak that I get either as a resonating buzz when playing (around open A), or if I push down on the bass when its standing upright on the pin.
Explains why the resonating buzz only happens during playing if standing on end pin - I don't get it if lying flat, or tipped upside down on the scroll (yes I tried that when working out where the buzz/creak was coming from).

Oooh my, that sounds like taking the top off to investigate. Ain't gonna happen before some major life changes round here. Dammit.

 

[KUNGfuSHERIFF]

Something’s loose. Getting the top off will be a battle. The factory used WAY too much glue. Ask me how I know.

 

[PaulKing]

Something’s loose. Getting the top off will be a battle. The factory used WAY too much glue. Ask me how I know.

Tell us the story man, with pictures if you have them! Were they already using too much glue in '37 I wonder!?
Ah well... she'll be going into semi retirement for a bit then. I can still record by taking end pin out and standing it on a box/cushion to take the weight off the end pin. But its not gonna get better on its own is it.
Cheers.

By the way what part of the world are you in these days? Didn't you ship off to Australia some time back in the RockabillyBass.com years?!

 

[KUNGfuSHERIFF]

I had a nearly pristine ‘35 that I took possession of with a sprung, glue-starved bass bar that was flapping in the breeze from the bridge down, allowing the top to sink. The bass had been stored in a closet for 30 years.

I’ve popped a few tops, using my trusty Swiss Army penknife blade, and never had to work that hard to get a top off (even in high school!). Rebuilding the torn-up edge took days. Absolute bastard of a job, but it got done.

You must be thinking of someone else. I’ve never been off North America. But it’s nice to be remembered.

 

[PaulKing]

So tell me, is the bottom block supposed to be glued to the bass top (and back), down there near the endpin?
Logic tells me the bottom block is rotating slightly under string tension, though still attached to ribs.
The buzz seems to be coming from the area the front contacts the bottom block.
If glue here is supposed to stop rotation that would explain both the end pin angle and the buzz.

Am I on the right lines?

 

[SAlcott]

So tell me, is the bottom block supposed to be glued to the bass top (and back), down there near the endpin?

Yes.

Logic tells me the bottom block is rotating slightly under string tension, though still attached to ribs.
The buzz seems to be coming from the area the front contacts the bottom block.
If glue here is supposed to stop rotation that would explain both the end pin angle and the buzz.

Am I on the right lines?

 

[PaulKing]

Yes.

Thanks buddy.
Hmm could be first major diy job for me.
Maybe i could pop just enough of the top to slide some hide glue in with a blade and cover that bit of the block. Or maybe I could screw my bass up doing it.