The next in my series of kindergarten woodworking questions

[Greg Guarino]

A small but significant amount of time has just opened up in my schedule. With any luck, I'll be able to devote some of it to my slow-motion project.

I'll be staining it, but I am doing some of the assembly first. So I'm worried about squeeze-out. The "ladder" sides are assembled, meaning, just the stiles and rail "rungs". I intend to attach the stiles of the front and rear frames to the "ladders" (with biscuits) before the final assembly, such that the final assembly will look something like this:

I *had* intended to glue up the front and rear stiles to the "ladders"

*before* finishing, but I have now thought better of that idea, principally because of the 3/16" - what's the proper term? Reveal? Shadow line? - visible part of the front and rear stiles where they join to the ladder stiles:

(you can see them in this drawing, on the left side)

I figure any remaining squeeze-out in that tiny corner would be a bear to sand out. Now I think I'll mask the area of the front and rear stiles that will be glued to the side (ladder) stiles and prefinish.

So (finally) the question:

If I run a strip of tape that is wider than the area to be covered, then use the ladder stile as a cutting template, I figure the masked area will still be a smidgen too wide; I'd rather the finished area continue under the edge of the joint a very small amount. To accomplish that, i think I'll draw a fine pencil line with the template, then cut a little inside of the line.

Good idea? Bad idea?

[Leon]

Things to consider. Glue in the holes of all those dowels should be sufficient to hold this assembly together, just a bit that would insure no squeeze out.

You can mask tape the area and exacto/utility knife out the sections that you want to stain. You can also reduce the width of the masking tape after laying the tape.

This is what I did here. This previously masked strip was masked with

3/4" tape but I trimmed one edge so that the masked area was approximately 9/16" wide.

I put the piece that was going to mate in place and drew a line along the joint line on both sides. I placed one edge of the tape inside the line 1/16" on one side and then trimmed the other side back another 1/8".

Now having mentioned the masking part above. The stain and 3 coats of hand rubbed varnish, and the removal of the tape left a noticeable step between the finished surface and the wood surface. I am not positive that the masked surface that did not receive a finish was a good union between the mating furnaces. Ideally the surfaces should touch. I depended on the dominos to provide most of the the strength.

In this case for you, I would simply put minimal glue in all of those holes to minimize squeeze out and completely finish the mating surfaces. You are not going to need a lot of glue strength in this scenario.

Just things to think about.

[Swingman]

Never got a clear understanding of whether you are pre-staining and masking off the area that will have glue on it; or your masking off the area that will be stained?

The former (pre-staing) is absolutely the best way to avoid not have the problem with glue causing a problem with the finish.

If the latter, removing any tape, with or without a bit of glue on it, from between two pieces of glue joined wood can be a royal PITA.

Might want to consider another method, like letting the glue set for about 30 minutes and using a sharp chisel to remove it before it dries completely.

[Leon]

AND in these cases it makes sense to use a WHITE wood glue. It dries clear in the event you miss a spot.

[Greg Guarino]

I have indeed used a lot of dowels on this project, but the two surfaces in question will be joined with biscuits. I can't remember offhand, but I think I made 6-7 slots over a 47" length.

That's what I had in mind.

I had looked at your photo a week or so ago. I had it in mind when I was thinking about what to do on my own project.

I had not considered that the finish (likely stain plus several coats of Watco Danish Oil) might build up the height at the edges. I have only used Watco for test pieces so far; the build-up seems minmal. What do you think?

And here, I suppose, we can begin the trench warfare that usually accompanies the "do biscuits add strength?" question. :)

If you were stuck in a Festool-free area and were reduced to using biscuits, would that affect your decision?

[Greg Guarino]

The former. I think I'd need to be awfully perfect with the tape line to do it the other way.

I have done that, but only with the "safety-net" of prefinished surfaces to protect me. I worry that the line at the corner would still be visible after staining.

[Greg Guarino]

There's another thing I didn't know about. But in this case it's not merely the color of the glue but also the glue's ability to resist the stain that I'm worried about.

[nailshooter41]

Greg, I participate less and less these days in instructional areas unless it is with other professionals. I have found that most Google educated fol ks find their level of practical experience to be much more valid than my 4

0 years of trades work, so I have nothing to say of value. But... I get a charge out of you because you seem honest, sincere, ready to learn and impr ove, and are already on the road of being a great contributor. You are just a bit farther down the road (on the newer side!) than most of us here.

Enough of that.

You can put the frickin' biscuit discussion to rest here:

(This is what happens when you let engineers have too much time to figure o ut a problem).

It concludes definitively that biscuits add strength in different kinds of joinery, and provides the data to back it up. It discusses the use of mult iple biscuits, compares biscuits to tenons, etc. It discusses the use of bi scuit on certain types of joints, concluding that it adds strength in just about all applications. In some cases it adds a great deal, in some cases not so much.

Aspects not discussed in the abstract are the importance of keeping your bi scuits clean and dry, not using broken biscuits, and it only touches on glu ing technique. All information readily available, so no mysteries there.

I used to have a great .pdf somewhere that was generated by an engineer's g roup to study the usefulness of the biscuit joint in modern furniture manuf acturing techniques. It showed a great amount of comparative data that had a single tenon vs. two biscuits, then large tenons vs. three biscuits, and so on. (That is in the above linked abstract, too.) Interestingly, multip le biscuits are quite strong, and in woodworking they seem to be good enoug h.

One of the pitfalls of being self taught or starting the road of being a de signing woodworker is "over engineering" your work. This is usually due to lack of practical instruction from a trusted source, lack of training, or l ack of experience. As a professional that makes money with their woodworki ng efforts, time is money so the key is to make the project strong enough t o do its duty, and build it well enough to last for years if that is the du ty cycle you are after. As a home craftsman enjoying their weekend, it is easy to get caught up in all the hoopla about the joining techniques of the old craftsmen and then further discuss how well their efforts lasted.

When I was doing a lot of refinishing, I was surprised just how simple many joints were that I studied. Simple joints that provide plenty of glue sur face (I was bowled over and delighted to see Karl's work included half lap joints, as I was embarrassed to tell him I did that!) that can be held toge ther with a couple of 23 ga pins until dry hold up fine. Joints that were c leverly constructed to hide mechanical fasteners, etc. are great.

Read that abstract and you can see the value of multiple biscuits per joint when attaching edge to side grain wood. The other study that I had but ca nnot find included multiple biscuits in joints because they found the speed and accuracy of biscuit placement was quite good, along with its easy repe atability made multiple biscuits a good choice for a joining wood.

The abstract concludes with a bit of a tongue in cheek dissertation using a gorilla as a metaphor for all the guys that want to be able to stack anvil s on their pine magazine rack they built for their bathroom...

Keep at it! You do some nice work, Greg.

Robert

[Leon]

I could certainly feel the line and I am sure that removing the tape contributed to that. If you don't pull the tape when wet you will get that build up at location. Trouble is you want to put down several coats so you can't remove the tape before the first coat get rubbed.

You can also considering finishing the whole area and then masking what you want to protect and sand the area to receive the glue.

Biscuits do add strength but not so much as thicker dowels or dominoes/floating tenons.

Yes, I certainly use enough glue. Try what I suggested above, finish first, and sand off the area to receive the glue, use masking tape to prevent sanding where you don't want to.

[Swingman]

Good idea.

Little different situation, but by using tape narrower than the thickness of the stock, that is exactly what was done here:

Caveat: Be careful what you use to trim the tape with or you can easily cut into the long grain with a sharp knife/razor blade.

I found the best way it just lay the knife/razor blade on the tape, letting it hang over on one end, then pull up on the tape, pulling it into the blade to cut it, instead of moving the blade. Less chance of marring your wood that way.

[Swingman]

If I'm looking at the right place, I see no problem with biscuits. Basically long grain to long grain also, no?

[Swingman]

This works very well to do the above:

[Greg Guarino]

Yes. But Leon's advice was that "all those dowels" - had there been dowels - would have held well enough even if the only glue was in the holes. Thus, no squeeze-out.

But those joints will use biscuits rather than dowels. I have little doubt that a 47" x 3/4" butt joint would have plenty of strength even without the biscuits. What I don't know is if one can glue just the biscuits and slots (thereby eliminating squeeze-out) and hope for a strong joint. I suspect the answer (after the smoke clears and a truce is declared) is closer to "no" than "yes".

I'm leaning toward masking the area as I first mentioned, but I'm always happy to learn something new.

[Greg Guarino]

In this case the cuts would be covered by the other piece once they are glued together, but thanks for the tip.

I have several of those scrapers, but I don't think I would have thought to use them for that task.

I was admiring those bar stools again. Could I ask you what kind of stain you used?

[Swingman]

Considering the task, and the design, both which appear to favor insuring adequate sheer strength, I would try to get all the glued surface area I could get, so the answer would be "no", IMO.

[Greg Guarino]

It's not as if I don't sometimes decide to "do it my way" despite the advice I get here. Of course, there is frequently a wide band of variation in the advice, so it's sometimes necessary to cobble together what seems best according to my own intuition.

Having said that, I figure that a smart guy appreciates how much he doesn't know, and takes advantage of the fact that other people have taken on the task of making most of the mistakes already. Learning from

*other people's* mistakes saves time, materials and possibly bits of flesh.

I skimmed it. Interesting.

That's me all over, or at least until my current project. I have told my wife and daughter that in case of earthquake, hide under one of my projects. :) This project is much more "spindly", but still plenty strong, I'm sure.

This is

What sparked this discussion of biscuit joint strength was Leon's comment that I could avoid squeeze-out problems by only putting glue in the dowel holes. I replied that these joints would use biscuits instead, thus I would probably need to apply glue to the mating surfaces as well. While a relative novice, I've done enough gluing to trust an edge grain butt joint 47" x 3/4" even without the biscuits. I'm using the biscuits as much to make lining up the parts easier during glue-up (always the most stressful step for me) as for strength.

I had not thought of using biscuits side by side. Interesting. Surely not necessary in my current application, but interesting.

I believe I saw a Stumpy Nubs video in which he refers to guys who want to fill their drawers with rocks and chains and then yank them open abruptly.

Thanks for the encouragement. If I manage to get these shelf units finished, I may give myself a battlefield promotion from Kindergarten right up to third-grade.