First Build - Super Strat

[Prostheta]

I'm heavily considering writing about clamping today. I think in many ways it is misunderstood simply because you don't "see" clamping pressure. There is a good amount of method behind it other than "as many as possible!" or "good enough". I'd prefer to dispel some of weirdness caused by the large numbers I quote really, especially since I feel that I almost derailed @psikoT's ongoing build by illustrating them.

[Prostheta]

On 4/21/2016 at 9:59 AM, SIMpleONe89 said:

 

Without a doubt, far too few clamps. I'll run the numbers purely so we can see the magnitude of difference. Don't fear. There's a LARGE amount you can get away with if the area is not structural or critical to stability. Glueing a top is different to glueing say, a scarf or neck laminates.

A typical Strat shape is near as damnit 0,1m² in surface area. That's 155in². I use inches purely because pounds-per-square-inch is how most woodworking clamps are compared in terms of clamping pressure. Typical recommendation for hardwoods is between 100-300PSI, however this is for critical glueups. A little below that and you get merely "unsatisfactory", a WAY below that and you risk gappiness. For critical glueups, that might lead to stability issues and ultimate failure.

I'm assuming that you used four of those clamps, two either side? The bench adds effectively zero usable clamping into this I'm afraid. It's a small amount of pressure distributed over a large surface area.

Two medium duty clamps produce anything from 500lb-1200lbs of clamping pressure, so lets me generous and say you whanged these in at 1000lbs each. That's 4000lbs (doesn't seem it, does it?) over 155in², or 4000/155 = just under 26lbs/in².

Ideally you should have used four times as many clamps and added flat cauls either side to better distribute that pressure around the top evenly. Quite likely because of the lack of cauls, the areas that you did clamp would have been under satisfactory glueing pressure, whilst the areas furthest from them under far less hence the gappiness and lack of glue squeezeout. A lack of squeezeout shouldn't lead you to think "ah, too little glue" like some might have you think. It means "too much glue" in some ways, I wouldn't use it as any kind of indicator in that respect. I apply glue using a plastic notched plastering squeegee. Always gets the right amount distributed and shows excess/dry areas readily.

I'm sure that the top will only have cosmetic problems as you mentioned with the glueline. It's not a massively-critical area when it comes to stresses expected of it, so there's no real need to worry. If it were say, a thick top on a Les Paul then yeah. That's far more critical.

Sorry for the long post. I hope this adds some good info to your existing arsenal going forward!

----

For your next build (there will be one, right? ) I would recommend having at least 6-8 of those F-clamps. Additionally, grab a thick sheet of plywood or MDF to go on the "thin" side of the glueup and either a second one, or a thinner one for the back. Pressure from clamps radiates from the contact points effectively 45° outwards. The thicker the cauls, the better the pressure is distributed.

 

I really like this build and that you've put a lot of time and effort into documenting it. Certainly, enter her in next month's Guitar Of The Month when it opens next month! I look forward to seeing what other projects you've got going on in your head....

[SIMpleONe89]

Wow thanks for the post Prostheta! Very informative!

I think the picture doesn't show all the clamps I used. I have 4 F clamps, 2 G clamps and 2 quick clamps. I used 4 clamps on each side and the bench vise for the center. So now I know the vise isn't of much use I can do away with it. 

I was reading psikoT's post where you recommended cauls with the curved edges. I'll definitely use these next time. 

Also will it help if I screw down cauls from the top? I was thinking of placing a screws in the neck pocket, pickup cavities and tremolo cavity and screwing cauls into it. That way I can also align the top properly. 

[Prostheta]

The curved cauls are a great idea, however I have no idea on the optimal curvature or beam cross-section that would be idea for clamping. I'd suspect this could be tested however. A small F-clamp can put out a few hundreds lbs, so making a beam clamped at one end by a BIG clamp, then seeing if a small F-clamp can cause the entire beam to deform within its capacity might indicate suitability in terms of what is applied at the centre vs. losses at the edges. The thing is, I don't see how any caul - flat or convex - can add more clamping pressure than the clamps can put in in the first place. Conservation of energy likely has "a bit" to say about this.

I just see curved cauls as a great way to apply pressure into the centre, where most clamps crap out because of reach. Beyond that, a simple slab of plywood sheet is easier to apply (whang it on with some greaseproof/cookie paper!). psikoT's drawing over on his thread showed that the number of clamps isn't reduced by the curved cauls by any means. Just having eight reasonably-good F-clamps (or thereabouts) with a big flat caul gets you a reasonable glueup. You're within spitting distance, clamping pressure-wise. Double that and you're golden.

Slightly off-topic, however my wife and I are making a new sofa based around the Stickley Tsuba armchair design. This has cold-laminated bent arms (5x 6mm laminates) done over a large form. The approximate surface area is about 0,24m² and we used this many clamps:

 

That was the first glueup which was partially unsatisfactory. The second and third used perhaps a little shy of 30 large F-clamps rather than the smaller ones dotted in there, all tightened by hands with gloves on! Tiring and hurts the knuckles, whacking them on adjacent clamps. Still, that's maybe 30'000lbs of pressure over 372in²! That still only translates as 80PSI. Regardless, the last glueups were fine. I decided to share this because it illustrates how difficult it is to translate what you see with your eyes (a dense clamp festival) versus the numbers that constitute the "gold standard". Compare this to jointing a body blank, which has around 30in² of surface area being glued. Three good F-clamps knock that out at 100PSI. It's feasible to exceed the pressure range without even realising!

In reality we can get away with far less in non-critical circumstances. It's just good to know how it works, even if only for mental estimation.

This is great reading:

http://www.finewoodworking.com/item/27122/how-to-glue-up-joints-the-right-number-of-clamps

 

Just so you're not curious about what the end product of that process is:

[SIMpleONe89]

Wow you can totally write up that clamping article from the stuff we've been discussing. Once again thanks so much for the information. Very helpful as I advance into more builds. I definitely need to build up my clamp arsenal haha.

[SIMpleONe89]

Well I also think a sofa has to support the weight of people so I guess the huge number of clamps is justifiable! You can never have enough clamps!

[Prostheta]

It's a commonly-used phrase, yeah. It's just knowing how best to use them and what their effect will be on the job. Like I mentioned, three big F-clamps or pipe clamps do a body blank. Laminating takes LOT more pressure.

In many ways, this is a good argument for laminating top/bottom halves of a two-piece body blank before jointing them left-right. You've got half the surface area to get clamping pressure onto, plus far better reach from the edges. Never considered that before, however it makes a strong argument for it.

I learnt something today! woo

[ScottR]

6 hours ago, Prostheta said:

I'm heavily considering writing about clamping today. I think in many ways it is misunderstood simply because you don't "see" clamping pressure. There is a good amount of method behind it other than "as many as possible!" or "good enough". I'd prefer to dispel some of weirdness caused by the large numbers I quote really, especially since I feel that I almost derailed @psikoT's ongoing build by illustrating them.

See if you can find RAD's post that links to three articles detailing testing of glue types and clamping pressure. I'm sure it is in one of one of his hundred page threads and they would be  excellent to include.

SR

[Prostheta]

Very true.

[SIMpleONe89]

9 hours ago, Prostheta said:

It's a commonly-used phrase, yeah. It's just knowing how best to use them and what their effect will be on the job. Like I mentioned, three big F-clamps or pipe clamps do a body blank. Laminating takes LOT more pressure.

In many ways, this is a good argument for laminating top/bottom halves of a two-piece body blank before jointing them left-right. You've got half the surface area to get clamping pressure onto, plus far better reach from the edges. Never considered that before, however it makes a strong argument for it.

I learnt something today! woo

I was considering gluing half the maple top and body together but I wanted to route the pickup wire channels and do the control cavity plus try a bent forearm contour so it wasn't feasible this time round. I do have a neck through bass planned with laminates so I'll definitely glue the halves first. 

[10pizza]

great read and I hope my Zebracaster will turn out with the same stunning top!

 

how did you create templates for the body mounted pickups?

 

[SIMpleONe89]

1 hour ago, 10pizza said:

great read and I hope my Zebracaster will turn out with the same stunning top!

 

how did you create templates for the body mounted pickups?

 

Thanks! I'm sure yours will be great! 

I traced the outline of my humbucker and shaped it. In the past I couldn't get templates perfect so what I did was to create half the humbucker and flipped it over so that it was a perfect mirror image. 

[Prostheta]

The biggest problem people have when glueing together two ready-laminated halves is lining them up perfectly. Again, you choose your battles. Either laminate by halves and figure out alignment later, or laminate a far larger pair of workpieces and put the extra work clamping it up.

[SIMpleONe89]

6 hours ago, Prostheta said:

The biggest problem people have when glueing together two ready-laminated halves is lining them up perfectly. Again, you choose your battles. Either laminate by halves and figure out alignment later, or laminate a far larger pair of workpieces and put the extra work clamping it up.

I was thinking of using dowels to align the two laminated halves, or some sort of alignment pins that I saw another guy on YouTube do. 

Also I was wondering if the Spanish tourniquet with rope method works with electric guitars too? I've heard of poor luthiers who build classical guitars back in the day who use the tourniquet method to get consistent pressures. 

[psikoT]

9 hours ago, SIMpleONe89 said:

Also I was wondering if the Spanish tourniquet with rope method works with electric guitars too? I've heard of poor luthiers who build classical guitars back in the day who use the tourniquet method to get consistent pressures. 

I guess high pressure in big surfaces is not needed in acoustic building... I use rope to bind the fretboards, where the area to glue is just a thin stripe.

[SIMpleONe89]

2 hours ago, psikoT said:

I guess high pressure in big surfaces is not needed in acoustic building... I use rope to bind the fretboards, where the area to glue is just a thin stripe.

Ah ok! Thanks for that I might try that on my fretboard and hopefully get good equal clamping pressure. 

[SIMpleONe89]

I also managed to record a bit of a demo of this guitar and I'm very pleased with how she sounds. The Tonerider AC2 pickups are fantastic for the price. The Kent Armstrong is less impressive but maybe because I put it in the middle position. 

Clean:

Overdrive:

Distortion:

[psikoT]

1 hour ago, SIMpleONe89 said:

Ah ok! Thanks for that I might try that on my fretboard and hopefully get good equal clamping pressure. 

Just to keep clear, I use rope just to glue the binding to the fretboard, not to glue the fretboard to the neck. 

EDIT.- The guitar sounds fantastic, congratulations! That's the proof that you don't need a huge logistic to make a good instrument.

[SIMpleONe89]

Ah that would make more sense for binding! 

Thanks! Not having the right tools was harder but the end product was worth it! 

[Prostheta]

Time to get to work on the next one eh? 

[SIMpleONe89]

Btw, if anyone is interested in seeing my entire video build diary, check it out here:

I've since swapped the Kent Armstrong Dual Blades in the middle for an Entwistle AS57. It now sounds sweet and I can get strat sounds by coil splitting. Very versatile axe!

[SIMpleONe89]

I realised I never posted any demo videos, so here they are!

Clean:

Overdrive:

Distortion:

[Muzz]

That is a fantastic guitar it looks and sounds awesome, zebra stripes really do it for me 

[Andyjr1515]

Great sounds and fine playing!  The guitar looks really good indeed.  

[SIMpleONe89]

Thanks! I hope to do a demo of the second guitar some time this week. Too many projects going on!