Poor glue joins

Just glued two aussie blackwood planks together in the idea if making a strat. Only problem was that I didnt have enough sash clamps and hadn't got a flush join.

So the result is a visible dark line down the center.

Does anyone know a away to fix it or cover it up?

quite difficult to make a poor joint invisible if you are going for a plain color.

I once got fairly good result with CA glue but the joint still became visible after a couple of months.µ

you could rout a channel and inlay a (laminated) strip of contrasting wood

Do you have a table saw?

Rip that sucker down the glue line, and try it again.

In my opinion, if you have to clamp the $#!+ out of it to get it to go together, then the boards probably weren't jointed real well to start with. Bad glue joints don't typically hold up in the long run, so I think you would be better off fixing the problem now, while its not a big deal.

In my opinion, if you have to clamp the $#!+ out of it to get it to go together, then the boards probably weren't jointed real well to start with. Bad glue joints don't typically hold up in the long run, so I think you would be better off fixing the problem now, while its not a big deal.

+1.

Agree that ripping it and having another go is your best bet for success. Also, you simply must have enough pressure across the joint to create a strong glue joint. One way you can improve the mating surfaces if you don't have a jointer, or don't have a router setup you can use to joint the edges, is to glue some 100-grit or so sandpaper down to a smooth surface, and evenly rub your facing surfaces across the sandpaper.

If necessary, beg, borrow, or (not really) steal enough clamps to give it good pressure across the joint. If it's a good smooth joint, you can probably get away with a few as 3 clamps, but more is better. No need to crush the wood fibers and squeeze all the glue out, but establish good firm pressure all across the joint, with the clamps on alternate sides of the joint (front and back faces of the guitar blank) to establish as even as possible pressure.

3 clamps across the width of a body blank is plenty. There should be a clamp every 8 inches or so. You don't want to squeeze the glue out of the joint resulting in a " starved" joint. A properly prepared glue joint will hardly require any pressure to produce a good bond. Guys who know what they are doing with hide glue can just rub the parts together for gluing in many instrument applications with no clamps at all.

3 clamps across the width of a body blank is plenty. There should be a clamp every 8 inches or so. You don't want to squeeze the glue out of the joint resulting in a " starved" joint. A properly prepared glue joint will hardly require any pressure to produce a good bond. Guys who know what they are doing with hide glue can just rub the parts together for gluing in many instrument applications with no clamps at all.

+1


Here are some off cuts from some guitar blanks I was glueing up. The boards were about 1" thick and ~22" long. I used three clamps.

NV94iQ_kHf4

If the wood along the join doesn't touch 100%, will the joint 100% eventually come apart??

If the wood along the join doesn't touch 100%, will the joint 100% eventually come apart??

If the joint starts to come apart in one area, it will allow moisture to get in there and it will also allow more physical movement which will begin seperating the joint even more.

That makes sense. It's so difficult to get two perfectly flat surfaces. I've got a nice Delta 6" jointer and I've not quite mastered yet...seems it's more of an art than a science.


If the joint starts to come apart in one area, it will allow moisture to get in there and it will also allow more physical movement which will begin seperating the joint even more.

I found this interesting article on glue joints...what do you guys make of it?
http://www.oldbrownglue.com/pdf/HowStrongisYourGlue_FWW.pdf

I found this interesting article on glue joints...what do you guys make of it?
http://www.oldbrownglue.com/pdf/HowStrongisYourGlue_FWW.pdf

I remember when that came out in FWW; of note is that the composition of their bridle joints, plus the stress they're applying to it, don't really resemble the forces at work in a long-grain Tele glue joint. It's good stuff, though, but I find most folks stick with their preferred glue as much out of habit as anything else.

IMO, flat jointing surfaces are best achieved with a good jointer and little practice, a handplane with a bit more practice, or a flat surface with sandpaper (as per R Stratenstein's suggestion), plus some time and tedium. My preference is for the handplane, but I know it's not for everyone. Note that with any of these techniques, practice and attention are important; it's really easy to shape a subtle angle into your jointing edges with just a momen't inattention.

Good luck.

Interesting results.

That makes sense. It's so difficult to get two perfectly flat surfaces. I've got a nice Delta 6" jointer and I've not quite mastered yet...seems it's more of an art than a science.

Practice with your jointer on scrap. It does take some skill, maybe better described as learned technique, but a properly set up and adjusted jointer will easily produce the glue surfaces you want. Even a visible joint can be quite strong, but with a good jointed edge, you can glue up two pieces that are all but impossible to find the joint.

This is a glue-up clamp a welding lady friend of mine made for me to my own design - if you copy it, call it the Hasenfuss Clamp please! It eliminates 'clampzilla' as this lists calls it.

http://homepage.eircom.net/~jconsidi/guitar/P7160498.jpg

It produced the blank that yielded the body you see - eight glue joints there. I find that I can make good joins with a very small cheap jointer, as long as I run the two pieces together face-to-face so that any error in one is compensated by a corresponding but opposite error in the other - hope that makes sense. Ron Kirn put up a post here a few years back that made that point perfectly, he showed a steeply angled perfect joint in a guitar body.

I prefer letting the robots do my joining work as seen here on top of the tablesaw with some sandpaper.

http://jpbturbo.com/wp-content/uploads/2012/03/029.jpg

Do you have a table saw?

Rip that sucker down the glue line, and try it again.

In my opinion, if you have to clamp the $#!+ out of it to get it to go together, then the boards probably weren't jointed real well to start with. Bad glue joints don't typically hold up in the long run, so I think you would be better off fixing the problem now, while its not a big deal.

+1

Rip, joint and reglue.

And clamp the snot out of it!! Clamps that size are pretty cheap. If they are for hobby only head to harbor freight.

BTW - I have the same jointer and it's very difficult to get the tables "flat". Also make sure that your fence is at 90. Check at the beginning of the infeed table and the end of the outfeed table. It the fence has a "twist" and some of them do or it's not 90 you're edge may be flat but once glued together the resulting board won't be.

good luck!

kc

kc

That glue comparison article is the one I mentioned several months ago…. its interesting to see that Polyurethane (Gorilla) glue, touted as being "da bomb" came in last…..

but even at that…. for gluing bodies together… any of 'em is more than sufficient…

I use good 'ol yaller glue….. like most of the wood gluin' hillbillies I know of… unlessin I figger it's gotta come apart for some reason one of these days… then it's hyde glue...

r

clamp it with scrap...

vSwlM7cf6mo

I find that I can make good joins with a very small cheap jointer, as long as I run the two pieces together face-to-face so that any error in one is compensated by a corresponding but opposite error in the other - hope that makes sense. Ron Kirn put up a post here a few years back that made that point perfectly, he showed a steeply angled perfect joint in a guitar body.

^This - so simple, yet so many just don't get it.

…. its interesting to see that Polyurethane (Gorilla) glue, touted as being "da bomb" came in last…..
r

Didn't surprise me a bit. I used the stuff once and it failed in the glue joint when tested, every time. I use Titebond I or hide glue for all instrument things, and TB I or TB III for furniture.

If you can't afford steel clamps then ratchet straps are a good cheaper option, easy to store too..
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/267754_10150320102092049_5168217_n.jpg

Ratchet strap are a good option, I recently used them for the edge banding on a table top. But be sure to also use clamping cauls, otherwise the those straps can really bite into the edges of the body.

This is the setup I typically use.

http://i299.photobucket.com/albums/mm308/coltwknight/From%20Scratch/102_4420.jpg

(2) pipe clamps, (3) bar clamps.

Two of the bar clamps keep the two pieces in line because my pipe clamps are not parallel clamps. The pipe clamps by themselves would do the job just fine. The extra clamps just make me feel all warm and fuzzy about the job.

clamp it with scrap...

vSwlM7cf6mo

Very clever, I didn't realise where it was going! I'll remember that method.

Here is the suspect I am talking about

Is it ok for me to continue or should I try again

I would bandsaw along the glue line, joint, reglue.

You could route a channel along the glue line and insert a contrasting piece of wood.

you could do a solid colour on that one.... finish it as is...

and do a better glue line on your next one...;)

I glued my blank with three clamps. I don't know how it isn't a widely used method, but of you use a scrap piece of wood on each side of the blank the pressure will get applied evenly, also if you use a softer wood ie. pine, it won't dent the wood and you can't clamp to tight. My shop teacher had a jig where 2x4s were screwed horizontally to... I'll just make a paint diagram.. http://i.imgur.com/NbMZR.png