Best glue for joining wood

[Davo]

Looking to make a "seamless" transition of two pieces so I can make larger items

What's the best route to go with this?

I've called around and the price people want to do this for me doubles my cost (could buy twice the wood) compared to doing it myself

[jTr]

Davo,
More qualifiers are needed for proper advice:
- Do you have proper milling machinery such as a jointer, planer, sander?
- What species of wood?
- Have you a good set of pipe, bar, or premium parallel clamps?

jeff

[Davo]

Just my Shopbot aside from hand sanding and clamps

It will be already machined oak - 24x11

Basically similar to this video http://m.youtube.com/watch?v=liyDkxNGTUs

[Brady Watson]

Here's some glue joint testing by Matthias (https://youtu.be/14Mkc63EpMQ) - an interesting watch.

At the very least you want your lumber to start out S2S or S4S from your supplier if you don't have a planer and jointer. This of course depends on how you are going to glue up the material. You can often get by with a good rip on the table saw and thickness it via a planer. If you have to get one over the other, go with a planer.

-B

[Davo]

Since it will be for 3D work only

The Shopbot isn't good enough to machine the surface like a spoil board?

To make sure the edges are even I machined off the entire length of the board about 1/16" with a profile pass

[jTr]

Davo,
By taking 1/16" off the edges, you've effectively "jointed" the wood, so I think you've got the right idea. As to flatness, getting each face trued up with the surfacing routine should be fine, as most of the witness lines typical of this process will either be on the back of the board, or milled away in the carving process.

After watching the video, I'd interject the following:

- PVA is PVA, regardless of the brand. Clamp times, set times and strength difference from brand to brand is negligible, though I was mildly alarmed that he was able to break the boards by hand...

- Unless you enjoy uneven stain with blotches, ditch the wet rag idea. I tried it once. Wait 20-40 minutes and scrape off with a crisp-edge putty knife. Leave the remainder for the planer (surfacing) and sanding stages.

- I strongly urge you to stick with a type "I". The II and III are for moisture resistance and the result is a softer, more flexible glue joint. Put a drop of each on a surface to dry, then get a scraper on it after 24 hrs. Type I is crisp and brittle, while II and III are clearly softer. I've found this stuff can flex seasonally, resulting in a raising of the glue line. Not good for maintaining that "seamless" look you're after, especially in a highly detailed carving.

- An enjoyable part of mastering your craft is in selecting your glue ups for the most complimentary match. It is advisable to pair straight face grain edges that are perpendicular when viewed from the end, like quarter-sawn lumber. Otherwise, what looks good in rough stage can quickly become a wild pattern as the 'bot dives into those deep carving details. In the end, you'll be glad you do this in house, as you're not likely to get this level of attention to detail if it's outsourced.


Jeff

[barrowj]

I do glue ups almost daily and have never had an issue using just the basic Titebond glue, always "I" like Jeff mentioned.

Joe

[Davo]

Does it conceal pretty well for 3D finishing?

[Brady Watson]

Yes...as long as your two adjoining pieces have a good fit...the glue line is pretty much seamless.

-B

[Burkhardt]

Titebond is also selling a translucent PVA variety (http://www.titebond.com/product.aspx?id=e06720fc-44f9-42b2-8c5c-77e7d85cf624). But the improvement over regular type I is minimal.

[Herb Holmes]

I use plain old TiteBond I , I get pretty seamless joints , pics below are all 2 piece bodies

http://i832.photobucket.com/albums/zz246/adirondak50/2012%20build%20challenge/IMAG2390.jpg (http://s832.photobucket.com/user/adirondak50/media/2012%20build%20challenge/IMAG2390.jpg.html)

http://i832.photobucket.com/albums/zz246/adirondak50/mahogany%20build/DSC_0003-4.jpg (http://s832.photobucket.com/user/adirondak50/media/mahogany%20build/DSC_0003-4.jpg.html)

http://i832.photobucket.com/albums/zz246/adirondak50/p90%20build/101_0944.jpg (http://s832.photobucket.com/user/adirondak50/media/p90%20build/101_0944.jpg.html)

[tri4sale]

Those look good, with my eyes I can't find the seam in the first picture, pics 2 and 3 barely noticeable.


I use plain old TiteBond I , I get pretty seamless joints , pics below are all 2 piece bodies

http://i832.photobucket.com/albums/zz246/adirondak50/2012%20build%20challenge/IMAG2390.jpg (http://s832.photobucket.com/user/adirondak50/media/2012%20build%20challenge/IMAG2390.jpg.html)

http://i832.photobucket.com/albums/zz246/adirondak50/mahogany%20build/DSC_0003-4.jpg (http://s832.photobucket.com/user/adirondak50/media/mahogany%20build/DSC_0003-4.jpg.html)

http://i832.photobucket.com/albums/zz246/adirondak50/p90%20build/101_0944.jpg (http://s832.photobucket.com/user/adirondak50/media/p90%20build/101_0944.jpg.html)

[Ajcoholic]

- I strongly urge you to stick with a type "I". The II and III are for moisture resistance and the result is a softer, more flexible glue joint. Put a drop of each on a surface to dry, then get a scraper on it after 24 hrs. Type I is crisp and brittle, while II and III are clearly softer. I've found this stuff can flex seasonally, resulting in a raising of the glue line. Not good for maintaining that "seamless" look you're after, especially in a highly detailed carving.

Id like to add some of my experience here...

in 2010 I switched completely to Titebond III glue. Previously I was using several brands of industrial PVA's (all known quality brands).

TIII is more than 2X the cost of the others I was using. However, I find there are some excellent benefits. Longer open time. Cures in colder temps (without chalking up) than many others. One big one for me is the ability to be sanded (especially through the widebelt and on the edge sander) without gumming up the belts. It is amazing, but it just doesnt get soft with heat and stick to the belts. These may or may not matter to you. ALso, I like the tan colour (easier to see and clean off than the clear stuff IMO).

As for the "softer glue allowing movement" - I am saying, based on making door panels, table tops, gables etc etc - basically I run through well over 10,000 BFM of lumber a year in my business and it all gets glued with TIII. I dont have any issues with moving glue lines, or anything additional to what was experienced the last 20 years with other traditional white and yellow PVAs.
I see a lot of my work over time (due to repeat work from customers) and I always inspect - and have not seen any adverse movement, even on polished out tops and panels that were laminated with TIII from solid wood.

I have had this discussion with other woodworkers who are misled by the fact that the TIII does not get "as" hard as TI. However, if you let it dry a few weeks (not just a day) it certainly gets brittle/hard. I have glue residue all over the shop and trust me it gets hard.

Just wanted to offer my 2 cents, based of course on much experience though and many 5 gallon pails of glue :)

PS I forgot to mention, when I started using the stuff I did a test.. clamped a few maple blocks together and after a few days subjected to a force of over 1000 pounds trying to shear the joint (left on 24/7) After months, it did not move even a measurable amount (less than a1/2 thou) with my Mitutoyo machinist calipers.

[Bob T]

I have had good results with titebond 2 or 3. I formerly used a joiner, now use a joining blade on my table saw. I use biscuits if I feel I can. I have planed on my shopbot when the material is too big or heavy to run through a planer safely.

[dlcw]

When dealing with light colored wood (maple, ash, cherry, etc.) glueups, I use Gorilla wood glue. It is white and dries clear. For dark woods, I use Titebond II yellow glue.

If the glue edge is jointed properly (power jointer or hand plane), the glue line is invisible.

[joe]

My complements on the beautiful photo's and glue-ups.

While I almost never worry about seeing a glue up seam, no matter what adhesive used, there might be an issue on larger panels. None of the adhesives mentioned have "Gap Filling" qualities. That's because small boards can be put through a joiner. However for those of us laminating larger panels where a joiner is out of the question, it's necessary to have gap bridging glue. For example we completed a sign for the OKC Elephant Pavilion, at the Zoo. It was 6'x20' Then we completed a 4@ 6'X14' panels for apartment complex. With this kind of work Titebond would be a mistake. None of our lumber is kiln dried which means it will have a tendency to move around. Odd as it may seem once the panels are glued up there is little if any warping.

Epoxy is often suggested but like other glue materials it's so thin it's good to have a thickner. Weldwood is my hands down favorite. No failures over the years. It's available at most lumber yards and is cheap. I buy in small amounts keeping it fresh. But, keep in mind it's a powder to be mixed with water. It works best in a thick solution.

Joe

[dlcw]

I agree Joe. Now you are talking epoxy or poly (foamy stuff) glue. Both waterproof and gap filling.

[joe]

While epoxy is extremely tough, the Poly Foam you are talking about isn't used for exterior wood glue ups. If it's what I'm thinking of that expands while setting up. That's one of the weakest adhesives on the market. How on earth did they come up with the title Gorilla Glue?

Joe