Weight relief options

DiscoStu

I built a guitar many years ago but it's on the heavy side (9.2lbs) now that I have back problems.
I've shown it before on here, it's got a mirror front so if I'm gonna try to make it lighter it'll need done from the back. 
I've seen some chambering ideas online but would value the hive mind input as to which might be the best to get down to ideally 8lbs or under.

My Mirrortop:



And some relief ideas found online: 

barnstorm

The Swiss cheese approach never seems to make as much of a difference as people hope. Are you planning to do a mirror back as well once you're finished with the router?

DiscoStu

I'll put some kind of cover plate on it for sure, probably more mirrored perspex.
I like the lines approach of the first photo as it adds strength but the swimming pool route if the first LP is obviously the way to shift a chunk of weight. 

Roland

My top tip for heavily modifying a guitar: don’t. Make another one instead.

DiscoStu

Roland said:

My top tip for heavily modifying a guitar: don’t. Make another one instead.

It's already a heavily modified guitar as it started out as a totally different donor instrument before the project started!

Here's the back of it 

Winny_Pooh

I've not done it but the swimming pool route work well tonally for duo jets, in which case route the whole guitar and add a new wooden back.

andy_k

Be prepared to completely change the sound of the guitar, without taking as much weight as you want from it.
I wouldn't take anything out behind the bridge - but you could go open season on the top and bottom sides, and then glue back on some patches, just leave it solid along the centre.
Maybe try playing a modern weight relief Les Paul first to see what it feels like compared to a solid, or swiss cheese model, it is quite a drastic effect.
They have a bit of cheek calling them LP's really, more like Casinos.

fretmeister

I hollowed out an Epi Les Paul, drastically.

It only saved 300g.

I’d be amazed if you could lose 500g+ that you want. But if you try it then the hardware has to be in the mix too. So if Graphtech or Titanium saddles save 5g per saddle then you’ll have to go that hard. 

ICBM

Bear in mind that the neck and hardware probably weigh around 4lb, so the body will be around 5lb. To lose over a pound, that means you have to remove about a quarter of the total volume of the body - that's quite a lot even if you go pretty close to the front - basically it's going to have to be like the chambered Les Paul, even the modern weight relief probably won't be enough.

The new rear cover will also weigh possibly as much as half a pound.

stickyfiddle

Chambered for sure. 

Also what tuners does it have? You can easily save 250g if it has something heavy up there, and it'll help balance, which makes it feel more lighter

Sporky

Also I think it's reasonably accepted that chamber ING will affect the sound.

I wonder if filling the chamber with some sort of light foam would make another difference. I'm inclined to think it probably would. How expensive is aerogel? 

DiscoStu

The guy who did the stripes on the Hohner in the first photo reckoned it took 2lbs off.

If it's not going to be anywhere near that then there's no point doing it as it'll still be too heavy to gig. I can play it sitting down in the house but I'd love to get it out now that I'm back in a gigging band

fretmeister

There is no way just doing the stripes in that photo took 2lb off.

stickyfiddle

fretmeister said:

There is no way just doing the stripes in that photo took 2lb off.

I mean it maybe could've if the guitar was 13lb in the first place...  

ICBM

Sporky said:

I wonder if filling the chamber with some sort of light foam would make another difference. I'm inclined to think it probably would. How expensive is aerogel? 

Gibson did that with "Chromyte" - despite the artificial-sounding name, it was actually balsa wood... Ochroma pyramidale. 

DiscoStu

stickyfiddle said:

fretmeister said:

There is no way just doing the stripes in that photo took 2lb off.

I mean it maybe could've if the guitar was 13lb in the first place...  

From 12lb to sub 10lb, apparently.

https://share.google/gChgjAYSXErevMavp

BillDL

I think you should hollow out the guitar body as much as possible, seal the cavities completely and add a lighter type refilling valve, and pump in Helium until you're happy with the weight and balance 

I had an exceptionally heavy Tele copy with a solid ash body (already with a swimming pool rout) and a pretty chunky neck.  It was a cheap brand and a B-stock guitar and I didn't care how it looked, so I just bored almost all the way through the body in two places with a hole saw and crudely and quickly routed out in the middle, then screwed on some cover plates.

It DID change the sound of the guitar (for the better actually) but I really didn't notice the change in weight, so the body is now just sitting on a shelf doing nothing.  Had it not already had a swimming pool rout I MAY have noticed a difference in weight by routing it out there, but I don't think it would have made much difference.  The chunky neck must have accounted for a substantial percentage of the overall weight, so even swapping the locking tuners to lighter ones and trying to get or make a lighter bridge would hardly have made any difference.

I think you would have to go the whole hog and hollow your LP out radically like the one at the left in your photos to actually feel a worthwhile weight reduction.

DiscoStu

You want to hear the irony? 

It started off as a Godin Radiator...
Which had a swimming pool chamber...
And I filled it in...

Not my pic, but it was like this originally. The body is maple and I filled it in with mahogany.

DiscoStu

You got to bear in mind that I built it nearly 20 years ago, and slipped discs were nowhere on my radar.
I played it for years after it was built but then other guitars came along, and others, and now I'm at a point where my gigging guitars are 7lbs and 7.6lbs and I really feel the difference when I play my Mirrortop on a strap.
I'd love it to see a stage though... I might just have to use it for a couple of songs then go back to the Charvel.

I have another unaltered Godin Radiator (which is why I bought a second one for the Mirrortop project) and it weighs 6.6lbs.
As far as extra weight is concerned the Mirrortop has added body wood, acrylic mirror face, humbuckers, Gotoh bridge and Gotoh 510 tuners.

GSPBASSES

I thought I'd give you an idea of how much wood you have to remove to make a substantial difference to the weight of a TC body. 



This is a Swamp Ash body, 39mm thick, it's oversize by about 8 mm or more all the way round the outside.



So after the routing, we've lost over 2lb. 



But of course, when the cap goes on, it will add weight to the body. But then, when the 8mm is removed from around the body, I'm hoping it will still be under 4lb.

These are pictures that I'm going to be using in a diary build in a few weeks, there's going to be two of them, they will not be taken to a finish as the customer just wants body blanks and only the neck pocket routed.    

DiscoStu

That's great info @GSPBASSES thanks for that. 
If I did it I'd be doing a large rear cavity and then a cover plate. You got over 2lbs off yours, I might get 1. That would put it in the same area as my Ibanez Blazer and my Baja Tele. Still not as light as I'd like but certainly more usable.