long miters anyone?

[Warrior]

I own a ts75 w/ the 1400,2700,and 3000 rails.

I am currently on a job where I am making numerous columns and beams out of 3/4" qtr. ribbon african mahogany. the columns are (14) 14.5" x 14.5" x 7' , (3) 14.5"x14.5" x 12', and many more 3 sided beams and columns.
I had originally planned on using butt joints w/ dominos but am now leaning towards mitered corners w/ dominoes. This is due to the nature of the job and the look of different grain on the edge of vs the face stands out more than I had hoped.

I have (2) 4' x 7' mfts on the job to aid in the stock processing and assembly.

Does anyone have any tips for cutting clean, long, tru miters w minimal fuss?

Thanks,
Eiji

 

[Mirko]

Eiji,
I've cut miles of miters, with both saws, and I find it is easer on the saw if you cut @ 90 first then move the rail in a couple mm and then cut your mitre.
Always support the work whenever possible.
On veneered parts that are too delicate to use fiber glass tape I suggest using packing film (saran wrap works also)to wrap around the columns, this will cinch everything up tight and act as a clamp.
Do a test...but i think the dominoes will be overkill and will also make assembly difficult.
I've had good results with plenty of glue and tape, followed by a quick burnish of the glued corners. If you have room glue a block in behind, this will make up for any short comings of glue.
But overall I think the domino or biscuit will almost weaken it, the reason, they will not allow the mitre to fold up and cinch up tight at the point and work the glue back, this way almost ensures an air tight joint, where wood fibers come into contact with each other. The tape also stabilizes the wood acting like a hinge.

In the picture below almost every joint was mitered 3/4 mdf core mahogany

Mirko

 

[bruegf]

That's a beautiful piece of work!!!

I'm curious as to why you say move the rail in a couple mm when the saw cuts exactly at the top corner as you move from a 90 degree cut to a 45 degree cut?

Fred

 

[Mirko]

Thanks Fred,
There have been times where the point was'nt sharp and I do'nt risk it anymore, so I move it in now.
I find with my saw, I get the slightest amont of flat left, thats no good, it must be sharp.
Its very tough to roll the edge when there is veneer missing.

Mirko

 

[Brent b]

Hey Elji, if you do intend to go with the domino'd miters make sure you test on scrap.  Even on it's shallowest height setting it has the potential for penetrating the surface veneer (consider variations in material thickness too).  It's not like I know this from experience or anything.  Of course the domino's help with alignment but interfere with the glue up so use a slower glue too.  I've heard, but not attempted a jig method for putting mitered columns together which entails making a jig from plywood with a center hole cut out in the middle a bit bigger than the column; slipping this form over the column in glue up (actually a series of them varying with length of column) and using a shims to close up edges.  Dunno if this works but probably will try it one of these days.  Or, if your a Luddite, like some, packing tape and masking tape works wonders.
Mirko, did you make that helical stair.  If so I'm not worthy!!!
Brent

 

[Mirko]

Brent,
Sorry to disappoint you but I was responsible for everything but the stair, which was built by David Pomeroy in Halifax, however I was responsible for the veneer and finishing, which was custom made 3ply mahogany. The original plan was to have us work on it but time restraints did not permit us.
Being able to work with him, and witness him and his crew erect those stringers, I regard as one of my greatest accomplishments!
The Architect told me that staircase is the tallest helical in North America!

Elji sorry to high jack your post

Mirko

 

[bruegf]

Years ago I helped my Dad install a free standing circular stair he built for a customer.  It was an impressive piece of work.

Fred

 

[Amateur]

Mirko,
Where is your work and the stairs located?

 

[Warrior]

No worries Mirko. Thanks for the tips and beautiful work dude.

Also its Eiji not Elji.

Later,

Eiji

 

[Mirko]

A private residence on the island of Providenciales, Turks & Caicos Islands.

Mirko

 

[Dixon Peer]

I agree that the dominoes will complicate the glue up.  I think you may regret using them when you are trying to get everything in clamps and the glue is starting to get nice and gummy.

Were I to do these columns, I would be inclined to use lock miter tooling in my shaper.  Once you have the tooling set up properly it's a breeze, and the assembly is actually made easier.  Otherwise, Mirko's tape method is very good, and when the glue is set up nothing is going to move.

If you don't have a shaper, a router table will do the job.

 

[rich1]

I had some short miters to cut today (making a flag box) and I set up the TS-55. I checked the initial cut for square, then I dialed in 45deg.
While I was trying to set up the 45deg I  chickened out and went to the table saw. The reason I decided to not use the TS-55 is when you set the 45deg mark on the saw the little alignment line seems to have a bit of ambiguity (kind of like a pencil line vs a knifed line) in it's position. I can use a Tiltbox on the TS and know I have 45deg (well +/- 0.05 deg).

There is no way to verify your angle until after the cut using the TS-55, how do you guys set up for a miter cut?

Ric

 

[Dave Ronyak]

I have made similar joints by first cutting slots in the faces to be joined and using a spline to help align and reinforce the joint.  The slots can be cut on a TS using the complement of the angle used to cut the bevel [one cut with board flat on the table and the complement with the side of the board against the fence] or a router table.  I use thin birch plywood for the splines.  Mirkos method or some strap clamps work well for glueup assembly.  But a router bit designed for such joints sounds like a better idea than mine.

Dave R.

Dave R.

 

[Warrior]

Mirko,
I fixed the problem of the miter cut not being exactly on the rubber edge.
Eureka!!!!
I inserted a shim of plastic laminate between the front angle adjuster and saw base, re-tightened the screws, and voila no more moving the rail after the first miter cut. The cut quality is significntly improved as well because the blade is now toed up during the miter cut.
This was my only gripe with the TS75. It is now the perfect saw.

Eiji Fuller

 

[Mirko]

Eiji,

Great idea to fix the saw, Did you use post-form laminate?
Thats a major improvement and time saver thanks for the tip.

Mirko

 

[Warrior]

Mirko,
What is the difference between the plastic laminates?

 

[Eli]

Post-form is thinner? ???

 

[Warrior]

It must be the regular stuff then. I don't use alot of laminates in my work i work mostly with solid wood and veneers. I do use the laminate for making jigs, applying it to work tops, fences and such. I get it for free so why not. There is a laminate shop at my lumber yard where I can pick up large scraps and seconds.

 

[Mirko]

Eiji,
The "post-form" is thinner about 1mm thick, its used for the cove counters, its thin so it can be heated and formed.
"General purpose" Laminate or GP is about 2mm thick. Its used for in most cases where durability is required, or when the core you are pressing it to is substandard.
I'm going to "Fix" my saw too, and will post my results, thanks again.

Mirko

 

[Warrior]

It is the post form laminate then.

Eiji