Hey All,
Looking for some advice/help. I have 35 "L" shaped kitchens to build. I also have to cut and install the tops "on-site".
The Inside corner will be a 45+- miter cut. Does anyone have any experience using the Festool 75 plunge saw with track? Will it hold up running through 1.5" Birch about 70 times without burning up the saw or the wood, will it give me a nice plumb/straight cut?
If you-all have any better ideas, suggestions, anything at all... I appreciate any help!

Thank You,
Chris C.

Wow, that is a good question, I have never used a Festool T75, but I do own a T55, my feeling is it would cut that no problem, it will be easy to set up the saw and clamp the track so you get perfect cuts.
Use some sort of alignment fasteners like biscuits, dominoes or splines and some joint fasteners and you are done.
I did a bunch of those many years ago before they had the dedicated track saws, we cut all our mitered corners on a 10 ft sliding table saw. We used a fence and a router to make any small changes on site.
Have fun!😎

First iisue is you probably shold not do butcher block at 45 but that is none of my business. We have a makits setup like this and has worked great for years on butcherblock tops. Keepa very sharp handplane with you for touchups

I think you are in for a load of trouble with mitred corners on the counters. The joints will open up with seasonal movement of the wood. It is exaggerated with mitres. You would be way better off by butt joining with dominoes no glue in the front. Bonus is you will save 2' of material per kitchen.

I have used both the T75 & T55 for years. I refer to the T75 as the beast. I use it for solid surface countertops and thick material such as the butcher block. Never had issues.

It was fine, but you need to have a good feel and understanding for the saw's abilities and make sure to use the proper blade, saw speed, and feed rate. All can cause problems if you don't.

I too don't recommend a 45 degree miter though.

Good Luck.

Agree 100% on the mitered joint. Thank You for confirming my suspicion. I have a good feel for saw speed & feed don't think that will be a problem. Can you recommend a Blade for the Festool 75?
I would like to make this a one cut deal, I thought about trying to take two shallow cuts but I am pretty sure it will just increase the the chances of a torn-up kerf. I do have a sharp plane to clean any rough areas up.
More fun... No Backsplash other than a Stainless Steel sheet. So the butt Joint will make it a bit simpler to scribe backs to wall.
Thank You Guys, I really do appreciate your input and experience.
Chris

Made the changes to the top, (Miter Vs. Butt), as stated above I have saved over 70' of butcher block therefore I can justify more tools! We are a cabinet shop so of course we have a biscuit joiner but not a Domino Joiner so I am looking at the Festool XL DF 700.
So what do you-all think, Can I use the big domino's without tie-bolt fasteners? I can use pipe clamps to pull the pieces up tight while sitting on the new cabinets and allow glue to set. Issue is getting under the counter to access the fasteners is going to be difficult at best.
Another issue... I have to finish the tops in-house. Contract does not allow on-site finishing so no sanding & matching of tops.

Again Many Thanks,
Chris C.

Glue the dominoes into one side of the joint. Glue only the one closest to the wall on the other side of the joint. Over width slots for the other domino positions to allow movement. Hold pieces together with screws and washers through oversize pilot holes in the cabinets. Remember you are allowing for movement in the x and y planes of the joint.
Full waterproof finish on the joint faces before assembly

Thank You all for your responses. I do feel more confident with all of your help.
Chris C.

No matter what kind of joint you make you are going to get seasonal movement across the grain. I agree about not using glue, I live in a super dry climate and we used a spline and joint fasteners with no glue, the joints opened a bit, but very minimal. What Thomas said about finishing your joints before is a fantastic idea.

The general feeling about mitered tops is to not do them. There are occasions when you must do them to accommodate the Architect, Builder, Customer or your own personal goals.

There is a very simple way to make the miters work. You need to make the miter bomb proof. That could be a combination of splines, dominos, and a good adhesives like epoxy. Basically if you assembled you miter and left it on the work bench it would be there forever.

The trick is how you fasten it to your cabinets or table legs. You've got two options. You can either fasten one leg of the L hard to the cabinets, then fasten the other leg loose(3/4" holes with 1 1/4" fender washers) is the most fool proof way. Use a screwdriver to tighten the screws. Leave them a little loose. The counter is effectively sitting there under its own weight.

The other option is to fasten the mitered joint area (2" either side) hard to the cabinets. Then do the fender washer loose install on both of the legs. This reduces the visible movement 50% by sharing it on both legs.

You need to design the with cabinetry such that the minute movement over time is not apparent to the casual observer. Good thing is most countertops have a decent amount of overhang.

Please do not say this will not work, unless you have seen it fail. I've done this on 6 different projects over 30 years with no problems whatsoever. I would do it in my own house.

For instance if you had a 4'/4' L countertop you would typically fasten the miter hard and let the ends move. If you had a 4'/8' L counter top you would fasten the 8' length hard and let the 4' leg wander with the seasons.

Adam, I am not disagreeing with you that you have done it and it worked. However what you said in your last message that you fasten the miter and let the ends float has me confused as that is not how wood moves. The majority of the movement will be in the width of the countertop, there is very minimal movement in the length of the countertop.

The movement happens out at the ends of the legs. Depending on the length they will move laterally back & forth as the changes in moisture change the miter angle.

If you think about how a door casing moves throughout the seasons. When you install it the miters are tight and 45 degrees. As the moisture decreases(winter heating) the miter gaps at the bottom, which means the miter angles are 44.5. If you only nailed the header and left the legs unfastened the miter would hold(if you biscuited it) and the legs would move towards the middle of the door.

Ypu dont want to glue the 2 tops together at 90 degrees, the cross gain one will rip apart if you use dominos. The wood will shink and expand at a rate of 3/32" per foot. X 2' equals just under a quarter inch if you are lucky. Spline joint, no glue, butterfly fasteners underneath.

This has worked stupid well for me

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Wow! That is really nice. Just don't think I can do that on site, Really nice looking joinery. Can you tell how you were able to make the joint.

Chris that return email did not work. Resend to me. Thanks!

Chris, I cut those on the cnc. Left and right tooling, and I made a sweet parametric program to make everything adjustable.

Hey All,
We have a Thermwood CNC, that was my first thought. Not that I was going to try a dovetail but just a way to get a clean square miter cut + cut outs for the Zipbolt fastners. Our table is 5X8 so each leg would fit. I suspect you had to clean up the Dovetail inside corners, then press the legs together, that must have been very satisfying! I would just make templates, CNC build and finish at shop then install finished product. But I am restrained due to closed "U" shape of kitchen walls. So on site, a mitered corner would be difficult to put together, a butt joint on site is do-able. Dave 's mention of using Dominoes & having issues with the ends coming apart does have me concerned. So maybe no Dominoes or glue, just a spline w/Zipbolt's... Thank you guys for the advice.

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This would be a butt joint + zipbolts & a spline.PIA on-site but again do-able.
Chris

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for what you are doing id do the butt joint youve shown

I would be way more concerned with a sink in the butcher block than how much movement will be in the joint.
At least that looks like a sink unit.

Yes it is a sink cut-out. Not my problem, plumber gets to deal with that. I just made an abstract cut out, I have no idea of sink size or placement Fore & Aft. Just goes in that cabinet.

Having said that I bet they very well may ask me to do the sink cut out. Done this many times just not in 1.5" thick lumber. I would normally cut four 2" holes in the corners then skill saw the rest. I for sure will lay the polyurethane onto the edge. But I was just wondering what would be the best cutter to use for the 2" holes? Hole saw would just smoke + there not deep enough, Spade bit, I dunno I think it would tear it up, Forstner might take awhile & probably smoke it too, Auger ehh maybe just hang on :-)
Any thoughts

I template and cut the sink with the cnc. Sand and seal the cut. Overkill maybe. Give the client the sink cutout as a cutting board.
Impressed by the mitres holding together. I guess it is testament to good fit and strong glue.

Hey All,
This job is getting close so I started looking for a festool TS75 saw, in my search I came across the Mafell KSS 60 18M bl Cordless Cross-Cutting System, with a guide extension should work for the tops. Have any of you all worked with or own one? I do wonder about the stock thin blade to make a clean 90* 1.5" crosscut.
Any thoughts about this cordless beast :-)
Thanks Again, Chris