Author Topic: Is 5/16" too much to trim with one pass of a router?  (Read 2247 times)

nereo

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Is 5/16" too much to trim with one pass of a router?
« on: July 27, 2016, 07:04:02 AM »
hoping for some feedback before I tackle this project tonight.

I have a 7' section of countertop that I need to trim back with a flush-trim router bit to be flush with the layer below it.  It's 5/16" thick and 3/4" high.  The edge will be pushed against a wall so you won't see it (even the top lip will be covered by a backsplash) - but I'm just wondering if I can route through that much wood in a single pass, or whether I need to do it in multiple passes.

Doing this in multiple passes will be a PITA - it's too big to fit on my router table, and I don't have a 7' long straightedge to act as a guide. Only way I can think of doing it would be to cut and tack a 3/16" piece underneath to act as a guide for the first pass... though I'm open to suggestions.

Thanks for any input.

brute

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Re: Is 5/16" too much to trim with one pass of a router?
« Reply #1 on: July 27, 2016, 07:07:34 AM »
Replying to follow.

Not much help I know, but maybe someday...

Fishindude

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Re: Is 5/16" too much to trim with one pass of a router?
« Reply #2 on: July 27, 2016, 07:08:49 AM »
Could probably do it with a real sharp bit going slow.
I would definitely come up with some sort of straight edge clamp to run against.

nereo

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Re: Is 5/16" too much to trim with one pass of a router?
« Reply #3 on: July 27, 2016, 08:54:23 AM »
Could probably do it with a real sharp bit going slow.
I would definitely come up with some sort of straight edge clamp to run against.

Yeah... I've got a sharp bit but that is a lot of material to cut through. 
I realized I can probably rip a 1x4 to get a decent enough straight-edge to do a 1st pass and remove ~half the material.  It's going to involve a lot of clamping and re-clamping, but probably better than cracking out an otherwise finished counter-top.

As usually the sure way is probably the slow-and-steady way...

zolotiyeruki

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Re: Is 5/16" too much to trim with one pass of a router?
« Reply #4 on: July 27, 2016, 10:28:36 AM »
Doing this in multiple passes will be a PITA - it's too big to fit on my router table, and I don't have a 7' long straightedge to act as a guide. Only way I can think of doing it would be to cut and tack a 3/16" piece underneath to act as a guide for the first pass... though I'm open to suggestions.

Do this.  It's not that hard to tack a guide to the bottom of the countertop and route it twice. 

lthenderson

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Re: Is 5/16" too much to trim with one pass of a router?
« Reply #5 on: July 27, 2016, 10:43:36 AM »
You didn't say whether the bit is 1/4" shank or 1/2" shank. That makes a big difference in what you can do.

Most router's have guides that you can outfit them with that will let you set the depth easily to make several passes. I use my guide on my router quite often. For a one time deal, you can probably do it if you go really slow and with a sharp bit. You may end up with chatter and burn marks on the material but it sounds like that edge won't be visible.

nereo

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Re: Is 5/16" too much to trim with one pass of a router?
« Reply #6 on: July 27, 2016, 10:57:57 AM »
You didn't say whether the bit is 1/4" shank or 1/2" shank. That makes a big difference in what you can do.

Most router's have guides that you can outfit them with that will let you set the depth easily to make several passes. I use my guide on my router quite often. For a one time deal, you can probably do it if you go really slow and with a sharp bit. You may end up with chatter and burn marks on the material but it sounds like that edge won't be visible.

It's a 1/4" shank.  The router is a craftsman I inherted from my father, the bits are fairly new and still sharp.  I can easily set the depth to do multiple passes, but I can't envision how this will help since that wouldn't allow the bit to be 'guided' along the way.

Do this.  It's not that hard to tack a guide to the bottom of the countertop and route it twice. 
[/quote]
Your comment just made me do a face-palm.  It made me realize that I don't have to do the first pass from the top of the countertop and try to figure out some way of clamping a guide on... I can flip the dam thing over and and screw a guide in to the underside, then to my 1st pass with no fear of the clamps slipping and/or them getting in the way.  Pass #2 I flip it back over and use the bearing on the trim bit to keep it flush.

Thanks everyone for helping me figure this out.

a1pharm

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Re: Is 5/16" too much to trim with one pass of a router?
« Reply #7 on: August 05, 2016, 01:07:03 PM »
I used a  1.75 hp el cheapo router with 1/4" shank to "cut" 5/8" MDF along a length of 96" multiple times with a questionably sharp 1/2" cutting bit.  However, the sparking displayed by the brushed motor and eventual smoke of electronic death eventually forced me to get a 2nd and then 3rd router.

You can cut what you need in one pass, but be prepared to significantly reduce the lifespan of your router to do so.

 

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