Floating Tenon Problem

[Kenneth]

Hi Robert,

When I suggested the compression idea, I was not thinking of the pressure of the jig, but the pressure of the cutting tool itself...

All the best,

[toolman946 via CraftKB.com]

My thoughts exactly... Kenneth beat me to the punch.

I think that the longitudinal wood fibers are "compressing" slightly as the cutter makes a "shearing" cut along the same axis as the grain.

One way to test this theory would be to make both the end grain and cross grain cuts and then measure the mortises with a dial caliper. I wouldn't be surprised if the difference is more than a few thousands... and that would confirm this theory.

The remedy I favour is a swipe or two with a sharp shoulder plane. Veritas makes a nice one:

[nailshooter41]

I can never find my scissors. That's why I use colored masking tape that has a dovetail and pin patterns alternately punched onto it. I can have perfect dovetails in minutes! And it comes in four popular colors, too!

Some say it looks like the old fashioned shelf paper, but hey... who's looking that close!

I was only familiar in passing with the case build method, and was really interested in what you were doing. In the end, the finish product is beautiful. No kidding, beautiful.

But... as an aside, if the big one gets dropped when I am in Houston I'll race you for a spot inside! ;^)

Since I was brought up in the carpentry trades, I have difficulty getting off the path sometimes. I am a carcass builder, tried and true. I don't have any problems learning something new and enjoy doing it most of the time, but "the time" is a problem. I just can't learn it all, but that doesn't quell my interest.

Outside of a magazine or book, I didn't see any one else pursuing that method of construction when you started on your project, and haven't seen any mention of it since.

Prototype? More coming soon?

So will you go to 1/2" and use the interiors to keep it all straight and square, or will you use 3/4"? Sitting here thinking about it, I guess the skin would make the difference as the 3/4" seems to have as much movement as the 1/2" anymore.

Rockler. I have had good luck with their products, but never looked at finishing materials. I would swear from that picture you used some toner, though. No one colorant will get what I think I am seeing.

Tried and true for too many years to count. Good old bug spit.

Surely you jest....

3# Zinsser (off the shelf) cut 30% with anhydrous alcohol shoots a glassy finish that will make you wonder how you got so good. Use the 1.4mm aircap with the air control about 1/3 to 1/2 open, the flow control at about 2/3 open, and the aircap shooting in the vertical position. Adjust the flow and air until joy arrives.

Hold the gun a perfect 10" (maybe 12) off the surface (the convergence point of the airstream and material reach perfection between those numbers) and you are there, dude.

Seriously, if you are confident with a high pressure sprayer, you are well on your way. Even a CAS gun is a great choice. Think of it this way, the more material that goes on your project, the less is in the air.

The industry says it breaks down like this:

Rattle can: about 20% material on target

High pressure: about 30% to 35%, depending on material used

CAS (conversion compressor powered guns): about 60% to 65% material on target

True, single purpose turbine powered HVLP: Well... they lie. Manufacturers say they get as much as 90% product on target, but I don't think so. Maybe if they unhooked the gun and poured it out of the cup. I think a good number based on the amount of drift we clean up would be about 80% to 85% (these are just guesses).

I came up with the HVLP number with a friend of mine after we decided to calculate the amount of product it took to get a 3 mil finish coat on smooth wood. We actually measured the material, took out the thinner, etc. to get that.

I don't know why, (maybe others can chime in here) but the older finishes seem to like the CAS guns better than the HVLP gun. I am guessing it is because they were designed for the old high pressure formulas. Those were the days of metals in the paints, and using VPMT and Japan drier in the formula.

You had to have a pretty good idea of what you were doing. I made a painful mess of some finishes before I got the hang of that stuff. You do learn quickly though to mind every detail, as there is no such thing as a touch up on a sprayed oil finish. Touchup on oil based is actually called "refinishing" or "topcoating".

But you know, when finishing metal doors, I still go down and get that stuff and mix it up and shoot it with my CAS gun. A good oil finish blended with some "stuff" will dry extremely hard, abrasive and solvent resistant. Nothing else will do that right off the gun.

But today's finishes are a different breed, and they are all made to be spray friendly/compatible, if not spray only/recommended. And they are formulated for easy use in HVLP. Look at Barry; what could be easier than taking off the can lid, swirling the finish around and loading the gun? With a 4 stage, no thinning needed. I can shoot my conversion lacquer out of the can as well with no thinning, I don't though. (I am not trying to downplay Barry's skills, just make a point about the actual finish itself.)

Actually, it was at the Houston woodworking show where I met you and Leon that I tested the Turbinaire and sprayed unthinned latex enamel. That was the end for me, I knew I was going to jump in. I just didn't know which machine.

I don't want to diminish the fact there is a curve to learning HVLP, but it is NOTHING like learning high pressure guns shooting oils. If you are already used to thinning, mixing and shooting, you may already be on the road to another tool purchase.

However: fear not. Festool does not make a HVLP system yet. (Whew..!) But I'll bet if you talk nice to Leon he will paint some Gremlin green stripes on whatever system you buy. ;^)

Just funnin' Leon.

Robert

[nailshooter41]

Hey, Kenneth.

The point I was thinking of when bringing up that particular jig is that it holds the router in a perfect position, rock solid, and creates a near perfect cut.

Since the only voice we have heard from that indicates no difference in the fit from end cuts to face cuts when using that particular jig, I suspect that the jig may have something to do with it.

In the end, I don't really know. It is too easy to run the tenon over the belt sander for a great fit.

Robert

[Kenneth]

Hi Michael,

I'm sorry I beat you to it...

But if we are correct, another remedy would be a sequence of lighter cuts.

All the best,

[joe]

As long as you're testing this, test it with a straight cutter vs a sprial cutter (OP stated he was using a spiral cutter). I would think that the compression, if present, would be worse with the straight cutter.

my $.02, ymmv, etc....

jc

[Garage_Woodworks]

I already do that. No remedy. You still might be on the right track though.

[Swingman]

wrote

I was being facetious OK, but about the gel stain, Robert! :)

Yep, that's exactly the shellac cut I shoot with my little el cheapo HVLP rig from the BORG.

On that note, I've saved every post that you and Mike Marlow have posted the last few years on spraying but have never had a rig good enough to put most of the info into practice ... one of these days.

[Rick]

Leon,

I use a Multi-Router as well, so I don't think it's a method question.

Rick

[Pat Barber]

You say you shooting shellac now...

With what ???

Sw> I've taken to using Rockler "Mission Oak" gel stain, which is actualy made

[nailshooter41]

I didn't actually think you were going to run out and buy a new system... but you never know!

The stains that have won my loyalty over the last few years are the Old Masters gel stains. They seem to have just the right consistency, just the right amount of pigment, and their colors are really good. You can use them as toners as well as stain. They stick to everything, and when I was doing a lot of door finishing for a company here, I even used them to color fiberglass doors.

AHA! And here I thought you were a high pressure man.

Wow... that's pretty flattering. Seriously.

I think that exchanging ideas with Mike and Barry (and everyone else as well) are a great way to stimulate the brain to learn other things you didn't know about what you do. The internet has given us all a marvelous opportunity to take a look at just how others do things, in detail.

I have been really pleased to see someone like Charlie Belden ( charlieb ) come along that is a worse wonk than I am. When I get going on something, I have to know everything I can to speed the learning curve along. I don't mind sharing what I find, and sometimes typing it all out helps me define my thoughts. I like the stimulation of helping others, as well.

Like I have said before, I got into finishing by accident/necessity. It was imperative that I hit the ground running. I had NO idea that it could be as interesting or challenging as it is to be a really good finisher. There are just so many aspects of finishes, materials, etc., that there literally is no end. And like woodworking, since there is no end to the learning, and that is a very good thing.

I might add here too, that you have been very generous with you own time to just about everyone. And certainly the website you have put up has been a really valuable tool as to how things are done to a lot of us.

A tip of the hat to you as well.

Robert

[toolman946 via CraftKB.com]

No prob... great minds think alike! (lol)

Your's is probably younger, though... hence the speed.

[Swingman]

"Rick" wrote

are stunning), and your "What I Believe" statement is reflected in everything you see therein.

All in all, visiting your site and seeing your work is an inspirational experience, providing food for thought for every serious woodworker. Thanks for the sharing!