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Forum topic by AandCstyle posted 01-15-2016 09:22 PM 764 views 1 time favorited 17 replies Add to Favorites Watch
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AandCstyle

2569 posts in 1720 days


01-15-2016 09:22 PM

Topic tags/keywords: slab waterfall question flap sander epoxy butterfly

My son bought a slab that he wants converted into a coffee table. I have never done any work with slabs and know very little about the process. He & his spouse want a waterfall edge for one leg and the other leg will be a cut off from the narrow end of the slab, I think, because he hasn’t come up with an actual design for their slab, they just know they like based on pix they have seen. They want to keep the edge natural as much as possible.

I understand that 2 45 degree cuts are required to make the waterfall end. My circular saw will only cut about 1 7/8” at 45 degrees and the slab is almost 2 1/2” thick. What is the best way to make these cuts very accurately at 45 degrees?

I intend to remove all the bark on the edges, but are the edges then sanded and to 150G? What is the best way to sand the edges and still leave most of the edge variations? Flap sanders??

There are some small end checks and I intend to inlay butterflies to prevent future growth. Can anyone recommend an inlay kit and templates. I know Rockler and Woodcraft have them, but I am wondering if there are better ones available at more reasonable prices.

There is some rot and some insect holes. I will color epoxy black to fill these using black TransTint, but which epoxy is best to get the deepest penetration and will this have to be done in stages due to the heat produced by the curing epoxy?

I appreciate any assistance anyone can offer.

-- Art


17 replies so far

View pintodeluxe's profile

pintodeluxe

4854 posts in 2276 days


#1 posted 01-15-2016 09:36 PM

Oh, he wants a waterfall edge on a 2-1/2” slab… is that all. Sheesh those kids.
I think I might check out my local rental shop. If a large circular saw and Domino joiner were available, it would make your life a lot easier.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

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AandCstyle

2569 posts in 1720 days


#2 posted 01-15-2016 10:04 PM

Willie, they bought the slab and I am getting to expand my repertoire so its all good. :) Your suggestion is a good one and the local rental shop has a 16” Makita. I didn’t even know they made them that big. The brute weighs 28 pounds. They don’t have a Domino, however. Maybe I can figure out how to get him to buy one for the project, hmmm?

Thank you!

-- Art

View bondogaposis's profile

bondogaposis

4028 posts in 1814 days


#3 posted 01-15-2016 10:13 PM

Yeah, the beam saw should work, unless you could devise a sled for the table saw, being able to fully support it would be the challenge for that. I think you could make stopped spline for your miter joinery using a router, maybe several shorter ones, like mini dominoes.

-- Bondo Gaposis

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AandCstyle

2569 posts in 1720 days


#4 posted 01-15-2016 10:57 PM

Hey, Bondo, I thought about the TS. The sled is a good suggestion. I would just need to figure out a way to get hold the slab in place on the sled since it isn’t square, I’d have to screw on some hold down clamps in the proper locations. The first 45 degree cut would be doable, then there is the second 45 degree cut on the cut off to properly align. I’ll give it some more thought.

I am thinking about cutting a number of 1/2” parallel slots into the bevels sort of like dentil molding, then gluing 2” x 2” blocks into the slots on one side (the top), then gluing the second side (the foot) onto the blocks. I haven’t described this well, but I think it will work if I can get the slots to properly align between the two sides.

However, a Domino would be much easier if I had one.

-- Art

View Tennessee's profile

Tennessee

2410 posts in 1978 days


#5 posted 01-15-2016 11:07 PM

Not all waterfall edges are 45’. I’ve seen more than one that have a pronounced roundover edge, going into a vertical wall. The vertical wall could be either part of the slab, (if you have enough to make part of it the vertical), or some similar wood that is appealing to the slab.
What this means is you don’t have to cut a 45’ joint, you have to think in terms of a butt joint between the slab, (top), and the vertical connected underneath, (leg).
The slab would have a pronounced roundover that could be achieved with either a large, 3/4” roundover bit on a hand held router, or even making it by hand, rounding it over taking into consideration the grain and other peculiarities of the slab. All sanded together, to my eye it looks much more like a true waterfall, which is what the original term was meant to represent.
Just another method…

-- Paul, Tennessee, http://www.tsunamiguitars.com

View Luddite's profile

Luddite

171 posts in 701 days


#6 posted 01-16-2016 12:13 AM

Art,

Used a downward 1/8 bit with a guide bushing. Had a template of various size butterfly patterns. This and some good double sided tape works swell. I used 5/16 stock for the blanks and then did a 1/4 inch mortise. This leaves a nice reveal.

Edges. Used a saber saw to remove bark and sapwood and cut at angles. Found simple hand sanding makes the edge nice.

-- T Loftus -- Just on the edge of common sense

View Vincent Nocito's profile

Vincent Nocito

485 posts in 2827 days


#7 posted 01-16-2016 05:30 AM

Once you have the miter cut, you can do a miter dovetail key joint to help join the pieces. Google that and you will find jigs. It is like doing a very thick box. I use System 3 5 minute epoxy (Woodcraft #124269). I added a few drops of Trans tiny dye to color it. Make sure you tape off the area around the repair to avoid getting epoxy everywhere. Once it is cured, chisel or plane away the excess. Depending on the size of the cracks, you may want to butterfly both top and bottom. Flap wheel sanders will work or paint removal wheels work well. Check out FWW 222 & 252 for articles on dealing with slabs. What species is the slab? 150 grit may not be enough. I used Odie’s oil on my Nakashima table. Good stuff (also available from Odie or woodcraft).

View AandCstyle's profile

AandCstyle

2569 posts in 1720 days


#8 posted 01-16-2016 02:19 PM

Paul, thank you. I guess I used the term “waterfall” inaccurately since I am really looking to keep continuous grain flow for the top and the leg on one end. They think it is attractive that way. Personally, I would have made one like this and been happy, but the customer is always…..

Terry, thanks for the tips. A saber saw is better than my idea of using an angle grinder. That is a beautiful slab you put together. Mesquite?

Vincent, I like the looks of the miter dovetail key joint. I think it would really compliment the butterflies that will be in the top. I will dig out those FWW issues. It is black walnut. Thank you!

-- Art

View mahdee's profile

mahdee

3551 posts in 1231 days


#9 posted 01-16-2016 03:07 PM

I have made several of those and did one on a band saw which I had to use a hand plane to make the two pieces come together perfectly. In fact you have to do that regardless of what you use. The best way to approach it is to draw a line that connects the center points at each end. That line will serve as a reference point to draw your cut using a square against the line. As for the holes, fill them with a lighter sawdust and pour CA glue in them. I like to use 1/4” copper as a butterfly. Having one of these circular saws help.

-- earthartandfoods.com

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AandCstyle

2569 posts in 1720 days


#10 posted 01-17-2016 12:12 AM

Mahdee, thank you for the guidance. You did a fantastic job on that table, I hope mine turns out half as nice. That is the monster saw I intend to rent.

-- Art

View endgrainy's profile

endgrainy

237 posts in 1351 days


#11 posted 01-17-2016 03:05 AM

I don’t have much experience with slab work, but I’m hoping to do a waterfall table in the future. Please post pics as you build!

As for butterfly keys, I tried them for the first time on a recent project:

http://lumberjocks.com/projects/207530

I got some great tips from this video, no template needed. Just a bandsaw, marking knife, chisels, and a router:

https://www.youtube.com/watch?v=hvzu6fWFskA

-- Follow me on Instagram @endgrainy

View runswithscissors's profile

runswithscissors

2187 posts in 1488 days


#12 posted 01-17-2016 08:57 AM

I used a wire wheel in a drill to clean up the live edge in a slab of black locust. That’s after removing the bark, of course. Worked well.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

View Tennessee's profile

Tennessee

2410 posts in 1978 days


#13 posted 01-17-2016 01:13 PM

Stunning table, mahdee!!
And that saw is almost as big as you are. What a horse! I’d be scared to pull the trigger!

-- Paul, Tennessee, http://www.tsunamiguitars.com

View mahdee's profile

mahdee

3551 posts in 1231 days


#14 posted 01-17-2016 02:27 PM

Tennessee,
I know… I am a small built (5’6’‘)and that saw was very intimidating at first but in reality it is quite tame. To prevent kickback I have the blade fastener bolt slightly lose so (it is fairly tight but not tight, tight) if it jams, the blade stops. Also, I have to tie the blade guard up to prevent the blade from wondering off because the spring on the guard if really stiff. Someone said they had good luck using a oversize board as a guide so the blade guard would fully open before it reached the slab. At 45 degrees making a clean cut with this monster is tough; I haven’t been able to do it as of yet.

-- earthartandfoods.com

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AandCstyle

2569 posts in 1720 days


#15 posted 01-17-2016 11:20 PM

endgrainy, that is a beautiful table, you should be very proud of it. Thank you for the link.

run, I appreciate the wire wheel suggestion, although, I was kinda angling for a new tool…. haha

mahdee, that is an excellent suggestion re the saw and the blade guard. I had been concerned about using the beast, as well.

Thanks for all the input. It is greatly appreciated.

-- Art

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