Expert builders: let's talk about gluing and clamping

[Richey Kay]

OK - now I have your attention :)

I've been thinking recently about all of the conflicting advice I've seen about how long you need to clamp wood glue while its drying. Let's take it as read that I'm talking about white glue (Titebond, I currently have Titebond 3)

When I first started making CBGs (almost a year ago) I had literally no woodworking experience. The glue I bought said the curing time was 24 hours so I clamped the piece for that time. It was always a frustrating part of the build process.

A few months later I spoke to a joiner friend of mine and he said this was a bit daft. 24 hours is the curing time, but it doesn't need to be clamped that long. He said he usually leaves gluing as the last job of the day and will clamp overnight. At a push about 6 hours would do as long as the join is not stressed until the glue has cured.

I posed the same question to a couple of experienced builders on Ted's site, and they said 18-24 hours to clamp. I asked another and he said about 2-3 hours.

I asked a couple of guys on CBN and they said 4-6 hours.

For my last 5 of so builds I have been clamping for roughly 6 hours. For my design I need to glue the headstock, the heel and the fretboard, and by the time I'm ready to start carving, let alone string up (which I guess would 'stress the join') the glue will have well and truly cured. No bad side effects so far.

So... the question I'm asking, or the discussion I'm instigating, is how long should glued joints be clamped for making instruments? And hopefully when others come along in the future with the same question I had, they can have a good read of this topic and come away with a bit of insight.

Rick

[ChickenboneJohn]

It's utter sh*te for musical instruments...even of the crudest most base kind. If you need a gap filling glue, a decent two part epoxy is yer man.

[Uncle John]

Yup.  Sawbones.   Gorilla glue is not a good glue anywhere it is likely to show.  

Today I glued and screwed a projector to a neck and used that Elmers Glue Max.  Wood glue would not have worked.  Glue Max will work.  I will wipe of the over expansion and it still may show a little, but on the back side which I tend not to be fussy about/

[Sawbones]

Doesnt it suck to work on somebody elses mistake!

I had to start setting my guitars up at age 13 because if I took it to the shop,it came back worse.

[turtlehead]

I use 5 minute epoxy a lot of the time.  Gotta work fast, but it works well if you're prepared going in.  Mix in a little sawdust to fill gaps, or just use it straight for good clean joints.  I like to scuff the surfaces with 60 grit paper to help it grab and hold.  Clamp it for about 15-20 minutes and move on to the next step.  I can knock out a scarfed neck with a fretboard in a couple hours this way and be playing the same day.  Instant gratification.

[ChickenboneJohn]

There's loads of info on making hide glue out on the web, so I won't go through the fine details, but he's the important things.

Buy a decent glue in the first place (I'm talking trad. glue, in dry ground granule form, NOT bottled "liquid hide")

Get the proportion of the glue to water right, and take your time preparing it until its nice and clear, skim off any scum off the top of it.

You don't need a fancy double wall glue pot - I use a stainless steel dog bowl sat on top of a saucepan with hot water in it.

Only make up as much as you need at a time. Because it's a bit of a palaver making it, I tend to save up a batch of glue jobs and do them all at once.

You need to work pretty quickly  - once the glue is on the joint surface it needs to be positioned and clamped pronto before it begins to cool and set-up.

To release a hide glue joint, all you need is heat and a bit of moisture. The technique depends on the type of joint - some joints can be parted with a hot knife or an iron and a damp paper towel, others such as a traditional neck dovetail need a steam injection needle (but it's easy enough to make a steaming rig). 

[Sawbones]

Cool info,I was planning on buying "violin"/fiddle glue that comes in granuals for my next builds.Thanks for the tips!

[Uncle John]

Okay, CBJ and Silent.   I will try the epoxy mix in the future for gap filling.   Silent, did you know that Blind Wally Nelson epoxied his left ring finger and made it into a slide.  It was kind of his trade mark.

I looked up the hide glue.  step 1: obtain a large horse with a healthy hide.

[ChickenboneJohn]

Best is not to have gaps in the first place.

[Michael Fred Johnson]

Yesterday glued up about noon,went to the pub for the traditional sunday lunchtime session,siesta in the afternoon,took the clamps off this morning

[Sawbones]

How'd it look?

I can handle waiting if the thing is going to be cool,it just sux waiting 3 days on a failure.

Are you across the big pond or USA bound?

[Bad Finger (Eric)]

To get over the impatience factor I do two things.  First, as mentioned I try to glue up at the end of the day or before I'm switching gears to doing something else.  Second, I get a stock of blanks glued up in sequence, even if I don't have immediate plans.  If the clamps are empty, I try to come up with something to glue.

The necks I typically make are two pieces of 1x2 joined on the 2" face and sometimes with an intermediate 1/4" strip.  I have a few of these just sitting around anytime I get the inspiration to start a new build.  I'll make the scarf joint and glue on a peg head if there's another break in the action.  About the only thing I consistently have to wait for is the fret board.

I use both Titebond II and the Titebond moulding and trim glue.  The latter doesn't drip from the joint and dries clear.   I always let the glue cure at least overnight before unclamping and because I'm not a selling builder, the glue gets a full week or more to cure before I string anything up and play.

[14 buck bass (aka antonio)]

cbj, thanks for hte info on the hide glue, I had ran that question acrossed the board a time back .  and ended up using titebond on my last acustic bridge because i didnt want to use bottled hide glue.  slowpaw awesome technique for keeping slipperyfretboards from drifting . thats my biggest pain in the rumpskin. Ted crocker also recommends a little salt or sand to keep from drifting.  good tip too it works great so far.  Eric ive never tried the trim and molding glue, the biggest headache i have is constantly cleaning the fretboard and neck joint with a moist towel during clamp up to keep all the titebond drizzle off of the neck.