Scratch: Electrics cavity depth question

[GregLane]

I am building a scratch SG from Queensland Mahogany and have been very slack not putting in a build dirary. I have the photos so will get around to it soon.

I am about to cut the electrics cavity and seeking advice on how thick I should leave the top of the guitar.

The pots I purchased have a 3/8" (9.5mm) bushing and by the time I have the washers etc. on it it looks like there is only about 5mm left for the thickness of the top (cap)

I have never measured the thickness of the cap on the kits I have built and searching the web gives me all sorts of answers around 1/4" (6.3mm).

It would be appreciated if someone who has built a scratch guitar can give me some clues and maybe anyone currently building a kit could measure the depth of a pot hole for reference.

Greg

[Trevor Davies]

Hi Greg,
I just finished an AG-2 kit. The body thickness is 37 mm and the electronics cavity is 32 mm deep.

Regards

[Simon Barden]

4-5mm is a pretty standard depth for the top of a control cavity. It's certainly the depth you'd have if you had a ply-topped guitar. With long-shaft pots you can go deeper if you want, but 5mm will suit medium-shaft pots. Short-shaft pots are really only for direct scratchplate mounting.

If you're worried about strength, some makers countersink the pots slightly into the 'underside' of the top of the control cavity (it would be nice if there was a single word to describe it) so that it's a bit thicker everywhere else.

[GregLane]

Thanks Trevor
It's interesting that the AG-2 is 37mm. The standard SG is supposed to be about 35mm. My lump of Qld Mahogany was pretty rough but I managed to dress it to 34mm.
Looks like 5mm of the mahogany in the cavity will be fine. The Qld Mahogany has a similar close grain to the PitBull kit mahogany so I will go ahead as planned.
This is my first scratch build so small careful steps for mankind, as you can imagine.
Greg

Edit - Trevor I just saw your guitar on GOTM. Hope I can get mine as good as that. Good Luck

[GregLane]

Thanks Simon.
I purchased an Allparts SG wiring kit which came with the large pots so recessing them might be a bigger job. I will assess how things are going as I carefully route out the cavity.
My measurements today indicated that the 3/8" shaft is just long enough. Anyway I can get longer shaft ones if necessary.
5mm of this heavy Qld mahogany would me much stronger than ply.
Thanks again for your advice.

[Cliff Rogers]

What is Queensland mahogany?
Google is not very clear, it suggests red or white mahogany and yellow or white stringy bark.

[Simon Barden]

It's not a real mahogany, it's a eucalyptus variant that looks rather like mahogany.. There seem to be red and white variants, so as it matches the kit mahogany, then it's probably the red type, as the white type looks rather more maple-like to me.

True mahogany is of the Swietenia genus, then you get related wood types, also often given a 'mahogany' title such as those of the Khaya and Meliaceae genus. The eucalyptus 'mahoganies' just look quite similar, and the 'mahogany' title is really a sales/marketing, rather than a scientific term.

https://www.wood-database.com/wood-a...s-the-lowdown/

[GregLane]

Hi Cliff
The Queensland Mahogany is Eucalyptus Resinfera.
They say it makes a great construction timber and good for wharfs. Guitars????
It is about the same weight as mahogany and maybe bit harder.
I got it cheap to make a table decided a guitar might be worth a try being a rank amateur.
It has a nice light red colour
I will put my build in a diary shortly. Been slack.

[Cliff Rogers]

Arh, red messmate, hard and heavy.

[GregLane]

Cliff
Is messmate a local term? Guitars ??
My wood came from Gove