Can a glue up be this complicated?

[dennis thompson]

I subscribe to FWW & enjoy reading it, although it is far, far above my skill level. I'm putting together a small butcherblock (about 21" by 32") for my wife to place on our granite counter to work on. It's 12 hard maple boards of just under 2" wide each. I saw an article in FWW about how to do perfect glue ups so I read it. It can't be this complicated, they go into formulas for the number of clamps, pressure on each clamp based on sq. inches of the top , different pressure for different types of wood, etc, etc. I just want to glue up my butcherblock, given that it's 32" long, how many clamps would you recommend I use on it? I plan to just glue up one board at a time and use Titebond III glue
What would you finish it with?.
Thanks
Dennis

[mike holden]

dennis,
It is NOT that complicated!
Apply glue to both surfaces, clamp with enough clamps and pressure to get a bit of glue squeezing out all along the edge and let it sit over night. Done.
There are niceties, such as scraping off the squeezeout when the glue just sets, and others that come to mind, but wet both sides with glue, clamp, and wait for the glue to dry is the simple basics.
This is not rocket science, even though some people make it seem so.

Note that I am not disagreeing with the findings, but simply stating that the degree of complication is not necessary.

On a 32 inch glue joint I would use 3-5 clamps, alternating the side on which the clamp bar faces.

Finish, well, for food use, I would consider a simple mineral oil finish, or a finish labeled "salad bowl" or "food safe". Definitely an oil finish as a film finish would be inappropriate for cutting on. (it would get cut, then lift)

Mike

[Michael Schwartz]

Glue ups are pretty simple.

The key is to be prepared, have everything you need (clamps, cauls, dead-blow mallet, damp rag, glue, glue spreader, etc... at arms reach.

Its a good idea to do a dry assembly with clamps so you can get a feel for how you are going to add clamps, how many, and where, and identify any problems such as gaps you might need to go back and fix.

You really don't need that much pressure with good glue joints. good pressure will produce an even squeeze along the glue line.

If you encounter excessive slipping during glue up try only applying very light clamping pressure initially and steadily increase it as you add more clamps and a bit of glue has had a chance to squeeze out. Also adding cauls, and clamps to keep an assembly aligned works wonders .

Using biscuits, or dominos etc... on very large panel glue ups can help with alignment as well.

If your working with a very large or complicated assembly its a good idea to use a glue with an extended open time such as tight bond extend, or a slow setting epoxy's, some of which will give you as long as a 6 hour open time

[Robert Parrish]

Woodsmith had an entire show on making butcher blocks yesterday. Check their website and see if they have a video. And no glue ups are not complicated unless you make them.

[fRED mCnEILL]

There is no question that all the formulas etc, mentioned in FWW come into play. But who cares. Most people that drive don't have a clue about the mechanicals of a car, they just drive it. Make sure you have enough glue and that you have enough clamps to get pressure everywhere (as evidenced by the squeeze out) and go for it.

Fred Mc.

[John Harden]

The FWW article was demonstrating how clamping force is spread and is designed to inform you so that you can make intelligent decisions after you gain experience. I don't believe the authors intent was for WW'ers to break out a calculator to determine clamp types, locations, etc., for every glue up. Once you understand the points covered, you will be armed with the knowledge you need to just pick up clamps and have at it.

Regarding finishes, any penetrating oil finish will be fine. Just don't use a surface building finish like poly, etc.

You don't need to use one labeled as "food safe". All of them are AFTER they have cured. That's the key. A rule of thumb is if you can still smell it when you place you nose on the board, it's not safe to use. You can speed this up a little by exposing it to air and light, but it will still likely take at least 10 days. Some I've used take almost a month.

Having said that, due to the life cycle of a cutting board and how often is is washed (by hand), any penetrating finish you use will break down quickly and the surface will become dull looking. That first coat of finish is just designed to soak into the end grain and help repel water from getting too far down into it. After that first coat, I'd just use butcher block oil or mineral oil. The're the same thing, but the butcher block stuff they sell locally here has a pleasant lemon scent.

That's my .02.

Regards,

John

[Howard Acheson]

An excellent treatment for wooden food preparation surfaces like cutting boards and butcher blocks is a mixture of mineral oil and either paraffin or beeswax. This is what is used on many commercial wood surfaces. It will last longer and be more protective than just mineral oil. Mineral oil can be found in most supermarkets in the pharmacy section or in a true pharmacy. Paraffin is found in the canning section of the store or in a hardware store.

Heat the oil in a double boiler and shave in some wax. The exact proportions are not critical--a 5-6 parts of oil to one part of wax will work fine. Stir the mixture until all the wax is liquefied. Apply the mixture heavily and let it set 10-12 hours or overnight. Next day do it again and continue until the wood will no longer absorb the finish. Let it set for 10-12 hours and then lightly scrape off any excess. Then buff it with a rag.

Reapply whenever the wood begins to look dry.

Never put a wood board in the dishwasher and don't soak it in dishwater for long periods.

[Dan Forman]

Here is a great video on the subject by Charles Neil.

http://www.youtube.com/watch?v=xq2pb_LfOBo

Dan

[Frank Drew]

Glueups shouldn't require a computer to figure out, but they can, nevertheless, be exercises in controlled chaos, with all the attendant stress. I say that because I'd probably glue up the whole thing at once, using something like Weldwood's Plastic Resin Glue for the long working time, but only after doing the dry run suggested by Michael to get everything in place and identify any issues prior to applying the glue for real. And apply clamps both above and below the work, as Mike Holden advises.

[dennis thompson]

Thanks for all the helpful advice. I am about halfway thru, I'm gluing up one board, let it dry for a couple of hours & go to the next, less stressful that way for me. So far , it's slow but coming along pretty good
Dennis

[Denny Rice]

There are just some people like the people who publish FWW, that try to "SUCK" all the fun out of the great hobby we call woodworking. Like others have posted, just be prepared and dry fit everything before putting glue on the first board, that way your sure to have everything you need.

[John Harden]

There are just some people like the people who publish FWW, that try to "SUCK" all the fun out of the great hobby we call woodworking. Like others have posted, just be prepared and dry fit everything before putting glue on the first board, that way your sure to have everything you need.


So providing real facts (versus conjecture) about how clamps work and how their force is spread is sucking the fun out of your hobby?

Interesting response.

To each his own.

Regards,

John

[Denny Rice]

So providing real facts (versus conjecture) about how clamps work and how their force is spread is sucking the fun out of your hobby?

Interesting response.

To each his own.

Regards,

John

John,

All I am saying is if everyone spends all their time doing advanced math trying to figure out how my pounds per sq/inch will needed to be applied to per premium "squeeze-out" then yes its sucking the fun out of woodworking. Look its taking two or more square and jointed boards, putting glue on them and setting them into clamps to dry. Why does this seem to be a hard concept.... We don't need to understand the scientific stuff why it works, all we need to know is if we do steps required we will get a good result. I'm sorry if I offend some but I really don't care about the scientific end of the process, I just know after 20+ years of woodworking what works.

[John Coloccia]

The article's interesting, but like everyone else I just wing it. I usually use enough clamps that it looks right, and then tighten them down until glue stops squeezing out. If I don't get even squeeze out, I used too few. If I run out of clamps, I used too many :D

I'm having a hard time imagining making a clamp so tight as to squeeze too much glue out. Has anyone actually made a starved joint like this and had it fail? I don't mean a starved joint from too little glue to begin with. I'm talking plenty of glue, plenty of squeeze out, and the joint fails because the clamp was too tight. I hear this warning all the time, but I don't know anyone who's ever actually done it. I've tried on test pieces and failed. I wonder if sometimes high clamping pressures are compensating for bad joints, and when the joints fail it's blamed on starvation?

[Howard Rosenberg]

That's the short answer.

But as others have said, it doesn't need to be.

The main thing is using just the right amount of glue, squeezing out just the right amount of glue and flattening the upper and lower surfaces.

HTH

Howard