PDA

View Full Version : Set neck clamping time



m0j0
23-10-2020, 08:11 AM
Seems like a simple enough question but I can't find a definitive answer. When gluing and clamping a set neck, how long should one keep it clamped? I was just going to leave it clamped for about 24 hours but some things I've read suggest you shouldn't:
a) Clamp it too tight
b) Leave it clamped for longer than manufacturer specifications

Since the bottle has no directions, I don't know what said specifications are but I believe Titebond says to clamp for 30 minutes and allow 24 hours before putting any stress on it.

I've got no dramas with the putting stress on it bit because I'll still be applying clear coats until the cows come home once neck is affixed. Just wondering what the consensus is on the whole clamping time thing.

37755

jonwhitear
23-10-2020, 10:34 AM
I haven't heard of a maximum time for clamping - I wonder how/why that could have a negative impact. The consensus seems to be to clamp for 24 hours, and then don't put any stress on it for as long as your patience allows.

Woltz
23-10-2020, 11:25 AM
When gluing anything stringed instrument related with titebond I leave it clamped for 24hrs to be sure it has cured properly. I wouldn't be too concerned about overclamping provided you aren't warping anything with the pressure.

The only time I clamp for less that 24hrs is when using hide glue which I wouldn't recommend using for this application.

Sent from my SM-G960F using Tapatalk

m0j0
23-10-2020, 12:14 PM
Sweet. Thanks, guys. 24 hours it is. It'll be at least two months before any strings go on it, so no dramas there.

Chaosblade
23-10-2020, 12:52 PM
I don't know about any disadvantages to leaving it clamped too long. But there's no reason to go too tight. You don't need any more pressure than it takes to hold the neck in place while the glue sets. At best overtightening the clamps does nothing. At worst it it damages your body and/or neck.

Simon Barden
23-10-2020, 02:30 PM
Titebond (website) says 24 hours for items under stress, and I think 1 hour minimum for non-stressed joints. A neck joint is definitely stressed, so 24 hours.

Yes, you can clamp too tightly if you manage to squeeze out almost all the glue (or so I’ve read/watched), but Titebond themselves have joint strength tables that show increased strength with increased clamping pressure. They go up to 100psi IIRC. So I’d clamp up pretty tight, just not excessively so. Your typical ratchet bar clamp won’t be able to overdo the pressure, and a G-clamp will struggle unless you’re really strong and go mad on the tightening or fit a tube over the handle for more leverage.

Sidewinder
23-10-2020, 09:21 PM
Unless I'm gluing up a large panel I use the one hand "quick grip" type of bar clamps squeezed pretty tight and leave it at least overnight; regardless of the joint type. In like 30 years of woodworking I cannot remember a glue joint failing.

fender3x
23-10-2020, 11:22 PM
Tight as you can go with a quick grip should be fine. But, just a small caution that overnight is not 24 hours. 24 may be overkill if you live in a hot, dry place. But if you live in a cool humid place, I'd err on the side of caution. I tend to interpret dry times as "at least".

Barry snook
24-10-2020, 12:24 AM
I’m about to do this and I got the 10ml bottle from pit bull with the kit, how much do I use? Half the bottle?

It has no labelling on it so no idea what it is, I’m guessing it’s titebond?

Simon Barden
24-10-2020, 01:50 AM
It's the same size bottle supplied regardless of the glued neck area of the kit, so you just use what you need. You don't want to apply too much otherwise it will just all get squeezed out when you clamp it and make a mess. I use a flat artist's paintbrush to thoroughly work it over and into all the surfaces to be glued - neck and pocket - and then clamp it tight. Too much glue and it can form a thick cushion that doesn't get squeezed out, and you want just a very thin layer of glue between the surfaces for the strongest joint. The thicker the layer, the weaker the join.

Beware of the glue squeeze-out. Some areas you can reach with a damp cloth to wipe it off, but others will be hard to access because of the clamps. I always put masking tape around the joins so any excess glue goes on the tape, not the finish.

Wash the brush out with water and it will be fine. If it's hardened by the time you get to clean it (concentrate of clamping the neck first before you clean the brush), just let it soak for a while and it will come off. You can also use a wet brush to access excess glue areas that you can't otherwise reach and then rub/soak the glue away.

Joe Garfield
25-03-2021, 11:06 AM
I think it makes sense to not leave clamped for too long. This is just an engineer's educated guess, but when you clamp the wood is compressed, and when you release the wood expands. So releasing the clamps when the glue has set, but may still have a tiny bit of flexibility, seems like a good idea.

In other words, clamping pieces together induces stress, and relieving that stress once the glue has fully cured will put that stress into the glue joint.