Attaching a large MDF router template to table top slab

[Dan Mitchell]

I'm making a coffee table out of Walnut. The slab's edges are tapered, and will now be cut in curves. I have rough cut the curves with a jig saw, and have made a 1/4" MDF template to apply to the top surface of the slab so I can use a router with bearing bit for the final sizing. I'm just not sure how to attach the template to the top. I have some very strong double sided tape which I have used in such situations before, but it tends to pull out some of the wood fibers (it's VERY strong), and I'm sure I would have to destroy the MDF template in the process of removing it, which I would rather not do in case I want to make another table. Plus, for accuracy, it would be nice if I could do the final fiddly positioning of the template with the means of attachment in place. Any ideas how I might attach this? Top is about 54 x 20 at its largest. Thought about clamps, moving them as I get to each point with the router, but I do want to be sure the template, which is slightly bowed, remains firmly flat to the top. Here's a pic of the 2 pieces. Any ideas?

TIA

Dan

[John Morrison60]

Dan

I have used the double sided tape sold in woodworker stores as "turner's tape".
So far it has done everything that I have tried, and did not damage any surface.

Good luck

John

[Jamie Buxton]

Clamps. Definitely clamps. Clamp the template to the top with four or more clamps, spread out. Leave three or more clamped while you move or remove just one while you rout. After you rout a run, put a clamp back on that area, and move on to the next area.

[glenn bradley]

For larger templates like that I frequently clamp the template on at the edge in 2 or 3 places. Route using the template till I get close to the first clamp, move it behind my path and route to the next clamp, move it behind me, etc. I will also use other clamps to attach the piece to my bench with the outer edges "in use" hanging off. These need to be repositioned as I pass by as well.

P.s. Jamie and I have a mind-meld going this afternoon ;-)

[Sam Layton]

Dan, I just finished what you are asking. It looks like your sides are straight. My sides were straight and my top was curved. I did not want to use double side tape. I made my templet from 1/2 mdf. I make it over size. on the side I screwed stock on each side to keep it in place. Then I used two clamps to hold it in place. Worked great and did not move.

Sam

[Dan Mitchell]

Thanks Sam, pretty nifty jig you made. Looks rock-solid. Unfortunately, the sides on mine are curved, and also tapered. Basically, I started with a rectangle, then tapered the edges by running it upright on all 4 sides through the TS, then curved each side & each end. That's my concern, I've put in a lot of steps on some pretty expensive wood, and so far so good, so it's about time for something to go wrong!!! :D

Here's a pic of the basic design:

[Dan Mitchell]

Dan, I just finished what you are asking...

BTW Sam, what can you tell me about that bit you're using? I was planning on using a regular 2 flute pattern bit, but that one of yours looks like it would yield a better cut. How long is it\where'd you get it\how much was it\how well did it work\etc., etc!!?? :D

[Sam Layton]

Dan, That bit cuts really clean. A few years ago I was going to Cerritos Collage, and someone had a source for the bits. They used them extensively in the chair building class.

I purchased the bit from one of the guys at the school. I don't remember who it was. I do remember that I paid $100.00 for it. The bit has 6 flutes, 1 1/8" in dia, and 2" long.

The package says PCT, must be the maker. Then it says, SPMAC1.125. It is made in the USA and It says Cobalt. I will Google PCT and see what I come up with.

The bit really cuts cross grain smooth. Sorry I can not be more help.

Sam

[Sam Layton]

By the way Dan, you may be better off with a 1/2" templet. Not as much flex and stronger.

Sam

[Sam Layton]

Dan, check out WWW.pctcutters.com (http://www.pctcutters.com)

[Dan Mitchell]

Thanks for the replies & Sam, for the link. I think I will go with thhe clamps. My concern now is more tearout. Maybe I'll post a 2nd thread on that. I'm REEEEEEAAALY starting to get edgy (no pun intended) about hosing this thing, now that it's coming together :D

[Tony Bilello]

I might be misunderstanding the question, but can you just use about a half dozen brad nails and air nail the MDF to the bottom of the table?
It should pop off easily enough or just screw the MDF to the bottom of the table.

[Sam Layton]

Dan, your going to be fine. I was thinking, you could use double stick tape and tape it to the bottom of the table top. That way if you get a little tear out when you remove it, it will be under the table.

Before you cut the real table top, try cutting a scrap piece of end grain.

Sam

[Dan Mitchell]

Dan, your going to be fine. I was thinking, you could use double stick tape and tape it to the bottom of the table top. That way if you get a little tear out when you remove it, it will be under the table.

Before you cut the real table top, try cutting a scrap piece of end grain.

Sam

Thanks Sam, the problem is, since the edges are tapered, I can only apply the template to the top. Actually though, the tearout I'm fearing at this point is from the bit itself. I am going to post a new thread on that, once I get some pics to clarify my concerns.

I appreciate your input.

Dan

[Tracy Hall]

BTW Sam, what can you tell me about that bit you're using? I was planning on using a regular 2 flute pattern bit, but that one of yours looks like it would yield a better cut. How long is it\where'd you get it\how much was it\how well did it work\etc., etc!!?? :D

Hi Dan,

I saw a similar (same?) router bit on the wood whisperer (http://thewoodwhisperer.com/103-flush-trim-bits/), he said that he got it from William Ng.

Tracy