Used Hide Glue on Top Plate---Seam Showing--Glue Too Thick?

[Andy Morton]

First, thanks for of the wonderful help from everyone here!!!!!

OK--after finally acquiring a beautiful, rock solid #7 Stanley Jointer Plane, I was able to get a nice jointed surface on my red spruce mandolin top plates (and flamed maple back plates). Was also able to glue and clamp the plates with hot hide glue. Followed all the recommendations (glue in double boiler at 145 F, well dissolved, a little thicker than water--maybe like maple syrup versus karo syrup, brushed on quick, speedy and well rehearsed clamping, pre-heated top plates)---but I did clamp the plates on top to keep them from buckling in the middle from the pressure of the long bar clamps attached at the sides. This may have inhibited a good tight fit and the hide glue contracting the joint tight as it dried and cured. Also, I could have applied the glue too thick anyway. Anyway a good learning opportunity.

My center seam is very visible...as you can see by attached photo. I would like to redo the joint...and reglue.

Recommendations--especially in heating and removing any of the glue and/or adding fresh glue?



I appreciate any help on this!!!

Andy Morton
Madison, Wisconsin

[Bill Snyder]

Cut the joint apart on a table saw and re-joint with your #7 Stanley.

[Rick Lindstrom]

I think it's just a bad joint. What does it look like on the other side? If it's good, it means your clamping was off and caused the side in the picture to open a bit.

If you're really going to use hide glue, make it fresh and have it mixed to a very thin syrup consistency. Think warm pancake syrup. Yum... pancakes. LOL Personally, I use Titebond. And I skip those handplanes and joint on a well setup jointer. Saves a lot of angst.

Anyway, if you have a bandsaw, run the blade through that joint, re-joint and try again. you won't lose enough to matter.

Rick

[sunburst]

Wedge-shaped pieces? They're difficult to clamp without the seam opening on one side. That's what drove me to learn to do rubbed joints. (Yes, more to learn... there's always more to learn.)

[Pete Jenner]

That's what drove me to learn to do rubbed joints. (Yes, more to learn... there's always more to learn.)

Is it possible to do a rubbed joint using Titebond John?

Cheers,

Peter

[sunburst]

I understand it is possible, but I haven't tried it, and besides, I think hide glue is a better choice for center seams for several reasons.

[Michael Lewis]

Like John, I have had rather poor experience clamping wedges. It CAN be done but life is SO much more enjoyable because of the rubbed joint. Make the joint fit well or you will have problems. I lean wedges against a vertical wall to dry, peak of wedge to the wall and resting on the peak. In this position gravity pulls the joint together, but if the wedge were leaned peak away from the wall gravity would tend to open the joint, though it may not do that. I put as little stress on that joint as possible until it's dry.

[j. condino]

Hot hide glue has a learning curve of its own; almost everyone will agree, but once you get it down, the results are far superior and worth the extra effort. I could ask a lot of questions about your methods, but it sounds like you are on the general path. Cut the seam open and try again. Most of the time a rubbed joint like John mentions is my favorite and makes an almost invisible seam.

Sometimes when I have a troublesome set of wedges, I'll glue on secondary small sections of spruce near the joint to act as "clamping stabilizers" and then carve them away after everything is settled. Here is an image of that method using two small c clamps ( moderate pressure, not crushing force!), hot hide glue, and the secondary set of PVC clamps as described in a thread last week.

Save the Titebond for picnic tables.....

j.
www.condino.com

[Pete Jenner]

Save the Titebond for picnic tables.....


www.condino.com

Sorry mate but I think many Luthiers out there would take issue with that statement.

[fscotte]

The point of planing the surfaces to a perfect flat joint is so you don't need clamping. A rubbed joint with perfect joints don't need clamping. If you're having trouble getting a perfect joint, then I suggest plane the best you can, the use 220 grit sandpaper to even the joints out. Then you can clamp if you like, or not, the joint will hold regardless. Many luthiers here use sandpaper on their joints. The seam will hold.

[Kip Carter]

So the 'Rub' is the use of sandpaper to match things up nice and tight... correct?
Kip...

[Lefty Luthier]

I use both hot hide glue and Titebond I depending on what my customer specifies. I have found no difficulty making a perfect joint with either adhesive when the joint is properly prepared. I clamp the two wedges using the vice dogs on my bench with a piece of steel angle over the center joint held down with a screw clamp on either end. I rub both types of adhesive to get good distribution but always clamp afterwards. Works for me.

[houseworker]

I use both hot hide glue and Titebond I depending on what my customer specifies. I have found no difficulty making a perfect joint with either adhesive when the joint is properly prepared. I clamp the two wedges using the vice dogs on my bench with a piece of steel angle over the center joint held down with a screw clamp on either end. I rub both types of adhesive to get good distribution but always clamp afterwards. Works for me.

I find it very hard to envisage a customer ever expressing a preference for Titebond when ordering a mandolin.

[Lefty Luthier]

I find it very hard to envisage a customer ever expressing a preference for Titebond when ordering a mandolin.

You would be surprised. In 2011 I built and delivered 9 mandolins and one guitar, of those 6 specified Titebond I throughout and 3 specified Titebond I to join the soundboard and backboard halves and the rim components with hot hide glue only to join the neck to the body and fretboard to the neck. Only one person specified hot hide glue throughout.

This photo is my glue method for the wedges.

[houseworker]

You would be surprised.

I am. I wonder what other luthiers make of this insatiable demand for aliphatic resin.

[sunburst]

It's easy to make far too much of what glue or adhesive is used. As long as we use a good glue or adhesive, the important thing is the joint. We need a good joint.

[fscotte]

I would guess one would choose Titebond over HHG especially if cost were a factor. For instance, $50 extra for HHG. Uhm... I think I'll take Titebond. And one might think it odd for one to try and save a few bucks on a mandolin that may cost $4500 or more. But then one wouldn't too surprised that people do funny things. Like pay $4500 for a mandolin and then try and save $3 on the strings.

[fscotte]

So the 'Rub' is the use of sandpaper to match things up nice and tight... correct?
Kip...

Take this advice with a grain of salt since I've only made 10 plates so far. But I find it far easier to plane to near perfect, then use some 220 grit to even out those nuisances to make a light tight joint when held up to the raging sun.

On some plates I've done straight plane work with no sandpaper. The others I use the sandpaper. I see no difference between the two. Of course my mandolins may not be together 100 years from now.

But I have some experience in furniture building and a sanded and glued joint is strong as an effer.

[Arne]

Well I'm not going to get involved in the glue debate but I think your problem is the joint isn't tight enough. When I was joining the plates with my instructor the most tedious part was making a tight joint. Using the jointer wasn't enough, I used a hand plane and set it very low so it would only remove an EXTREMELY small amount of wood (so it's just scraping off powder). After some careful planing I dry clamped and reclamped until I couldn't fit my finest feeler gauger into the crack. This took me many hours. If your wood is still slightly green it's best to glue it up the day you start or the wood will have warped by the next day.

[Bill Snyder]

... If your wood is still slightly green it's best to glue it up the day you start or the wood will have warped by the next day.

If your wood is slightly green don't use it until it is no longer green at all. Using wood that is not properly dried is a recipe for failure.
As for it taking many hours to get a good joint it shouldn't. With a well sharpened and tuned up jointer and plenty of practice you should get where it takes very little time to prepare the joint for gluing.

[Andy Morton]

Update---and thanks everyone for the help...I was able to get a really tight joint on my second attempt with a nearly invisible seam. By the way, I purchased the wood from Old Standard over a year ago...its really nice and well seasoned. Here some of my observations.

1. After upgrading to a #7 Stanley jointer plane (likely 20's vintage) in very good condition that I purchased from Ebay ($40---a great find), and upgrading to a Ron Hock Blade, I was able to get a perfect planed edge that closed very well in maybe three passes. I had resharpened the plane using the scary sharp method, with a micro bevel and slight back bevel. It was forearm shaver sharp. As I said in an early post---a rock solid and stable plane set up really helped.

2. I used a water/milk thin HHG mix, heated the room, heated the work pieces---versus thicker glue on my first attempt.

3. Used moderate clamping pressure (bar clamps with a flat surface for the bar that the plates could rest on).

4. Used very moderate pressure (weight) to discourage buckling at the center seam instead of clamping too tightly.

So..I think that I used too thick of a mix of the HHG and also clamped the center seam so much that the HHG could not draw the plates together when the glue dried and cured.

The use of HHG is really an amazing process and I can see why people are so fond of it---really works and is actually pretty forgiving.

Again, thanks!!

Andy

[Pete Jenner]

1. After upgrading to a #7 Stanley jointer plane (likely 20's vintage) in very good condition that I purchased from Ebay ($40---a great find)
Andy

Haha that's an understatement. It must be one the dealers missed.
I bit the bullet and paid $400 for my #8c type 12 with sweetheart iron. It was worth every cent though.

[sunburst]

I'm not sure I'd worry about it at this point, but "water/milk" thin is much thinner than I would really feel comfortable with. I like my hide glue to run off of a brush in a thin stream before starting to drip. Not as thick as Titebond, but thicker than cream.
Hide glue is glue and water. When you add water you displace glue, when it dries the water is gone, so more water means less glue left in the joint. Part of the process of a rubbed joint is expressing excess glue from the joint so that the film of glue is very thin, so a thicker mix leaves more molecules of glue in the joint.
With proper temperature control, glue that is not too high in gram strength and therefore too fast to gel, and good clamping of well prepared surfaces, the glue should not need to be too thin, and I suspect the glue being too thick was not the problem with your first attempt.

[Rave On]

I clamp one half vertically...with the gluing surface parallel to the bench facing the ceiling...then I do every thing you do, except two things:1 after the glue is applied to both surfaces, I apply the other half (the top piece) onto the bottom and then physically rub the surfaces with glue on them together. For a few seconds it feels like they have been greased...but quickly they get tacky and stick. As soon as you feel the tack, slide the sides into the correct position and leave them alone for 24 hours. You will have squeezed the excess glue out of the seam. The excess glue will be above the seam so it can be removed with a plane after the glue is dry. The hide glue will pull the sides together. 2. Don't use clamps. Just let the weight of the top piece balance. My experience is that is difficult to clamp wedges quickly, so clamps are more likely to hurt the joint than help it. You are really close. Rave on

[HoGo]

Andy, how did you clamp th epieces together? I had similar result on my first attemp many years ago when I followed all good advice but I applied the glue (to both sides) then gently pushed the joint together with plates on flat surface and then used clamps. If you are not really fast you won't be able to squeeze the excess glue out completely. Now, I rub the joint lightly to help the squeeze out till I feel grabbing and lightly apply clamps after that. Your joint should be nearly invisible right after clamping. I always do test "digs" with gouge to see it and if it's not good I part the halves right at that moment (may be pretty hard with HHG even after five minutes) and clean, let dry, re-join, try again...