# which bit for router sled?



## sunnybob (Apr 3, 2015)

I have a router sled, and want to know the best bit to use to flatten pieces of wood to a glue quality face.
For example, I have 2 pieces of walnut plank, each being a foot long x 8" wide, cut from the same large plank, and I want to glue them together to make a block.
So I need a completely smooth flat face to both.

I have used ordinary plunge bits, and even a bowl smoothing bit, but there are always lines left in the wood, making me have to sand them out, and often causing more uneven surfaces in the process.


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## Gene Howe (Jul 10, 2007)

This is what I use. Cut at about 3/32" for smooth surfaces.
Infinity planer bit.


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## harrysin (Jan 15, 2007)

sunnybob said:


> I have a router sled, and want to know the best bit to use to flatten pieces of wood to a glue quality face.
> For example, I have 2 pieces of walnut plank, each being a foot long x 8" wide, cut from the same large plank, and I want to glue them together to make a block.
> So I need a completely smooth flat face to both.
> 
> I have used ordinary plunge bits, and even a bowl smoothing bit, but there are always lines left in the wood, making me have to sand them out, and often causing more uneven surfaces in the process.


I used to use a bottom cleaning bit but found that a dish cutter gives better results.


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## sunnybob (Apr 3, 2015)

Gene, I shall have to see if I can buy them in the UK.

Harry, I used one of those but was not happy with the finish. I've used it in 2 seperate routers so i know its not a bearing run out problem.


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## JFPNCM (Dec 13, 2009)

I’ve used both the dish bit and a Freud bottom cleaning bit and generally prefer the latter. I recommend using the largest diameter bit for a smoother finish and as Gene points out, the thinner the cut the better.


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## gmercer_48083 (Jul 18, 2012)

Sunnybob, Check this out

https://www.routerforums.com/jigs-fixtures/139787-interesting-videos-flattening-slabs.html


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## sunnybob (Apr 3, 2015)

I have a power planer.Never use it because its so hard to control. i had never ever thought of using it this way.
I suspect I will in the very near future, Thanks.


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## timbrframr (Nov 2, 2019)

sunnybob said:


> I have a router sled, and want to know the best bit to use to flatten pieces of wood to a glue quality face.
> For example, I have 2 pieces of walnut plank, each being a foot long x 8" wide, cut from the same large plank, and I want to glue them together to make a block.
> So I need a completely smooth flat face to both.
> 
> I have used ordinary plunge bits, and even a bowl smoothing bit, but there are always lines left in the wood, making me have to sand them out, and often causing more uneven surfaces in the process.


I sometimes use a sled for recessing housings for timber frame joinery and have actually had fine results from a spiral uncut bit. That said, the below bit is supposed to be superior and I just got one so haven't had a chance to try it out yet. 

https://www.leevalley.com/en-ca/sho...ies/router-bits/110463-flattening-router-bits

I'll let you know how it works.

B


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