Delaruelle tuners

ChrisMartin · November 2019

I am fixing up an old Castelluccia which needs a few little repairs. It has the original yellow button Delaruelle tuners which seem to work ok except one has lost the plastic button. Luckily I have some old spares I kept just for such an opportunity but the question is does anyone know how to remove one of the buttons from a scrap set and then fit to the usable one, were they glued on? I am obviously reluctant to use any excessive force, it will just break, but I wondered if there is a known 'trick of the trade'; y'know like submersing in near-boiling water, or leaving it in the freezer overnight?

Bones · November 2019

I'm not sure what those buttons are like but modern tuners with plastic buttons I've done it this way. Make sure the hole in the button is free of any debris and the diameter is just a bit smaller than the barbs on the post and basically a line-to-line fit with the post diameter (or very light press fit). If you have to drill out the button at all, start with a small bit and slowly move up in diameter to the final size. Don't remove too much material on the diameter at one time or you may crack the button and don't drill too deep or you might break thru the other side and be sure to clamp the button lightly in a vise (wood or soft jaws). Grab the tuner body and line up the hole STRAIGHT with the hole in the button, put a small soldering iron on the metal post for just a bit. The hot post will soften the plastic just enough that it will just slip right in. Don't overdo it with the heat or you can ruin the button. Wear gloves if necessary if the tuner is too hot but you shouldn't need to since you really should not have to use too much heat with plastic buttons.

If it is a used button try lining up the barbs on the post with the deformations in the hole in the button too.

Again, go easy on the heat so you don't ruin the button. You can feel when it is just starting to soften and the post will just slide in nice and easy. Also, a light pencil or pen line on the post at the hole depth is a good indicator so you know when you are about to bottom out in the hole.

Good luck and let us know how it goes.

Bones · November 2019

PS- here's a good Stewmac post on this.

https://www.stewmac.com/How-To/Online_Resources/Hardware_Installation/Replacing_damaged_tuner_knobs.html

ChrisMartin · November 2019

The original Delaruelle tuners are not like you describe. They are all brass and the shaft where the button fits is a straight square section with no barbs. The buttons appear to be made from a phenolic resin similar to Bakelite which would make sense as they were standard fitment on a lot of old guitars before modern plastics were available. However, I have several old part sets I have kept for spare parts so I will experiment with the soldering iron to heat the shaft and see if that softens one enough to pull it off in one piece, then try to find an adhesive that works with phenolic, probably a urea formaldehide type.

As the gears and shafts are made of brass of course they do not wear very well over the years but I thought I would try for the sake of originality to make one good set from the best parts, but I suspect I may still eventually replace them with a spare set of the Selmer style covered Schaller Deluxe tuners I have here anyway.

Anyone else have any experience with Delaruelle tuners though?