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Crosscut Sled Warped

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Forum topic by fivecodys posted 08-15-2015 08:12 PM 1255 views 0 times favorited 15 replies Add to Favorites Watch
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fivecodys

582 posts in 1103 days


08-15-2015 08:12 PM

Hi guys,
I built a cross cut sled in October of 2013. I have used this many times throughout the year but today when I went out to make a few cuts I noticed that it had warped. The bed of the sled to the left of the blade has raised up almost 1/8” over the right side. I live in central California and it has been dry and hot. We did have a few days of higher than normal humidity a couple of weeks ago.

I did not apply any type of finish to the sled other than waxing the oak runners.
Since I share the garage with the wife’s car, my table saw is put away nightly. I keep the sled on the saw when stored and it’s covered with a nice cloth tarp. I’ve been doing this for years.

Any ideas on what might have caused this sled to warp all of a sudden?

Thanks in advance for you comments.

-- Chem, Central California


15 replies so far

View Bill White's profile

Bill White

4457 posts in 3427 days


#1 posted 08-15-2015 08:39 PM

The joys of using wood.
Not a smart a$$ed answer, but wood DOES move more than we’d like to think.
Bill

-- bill@magraphics.us

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Aj2

692 posts in 1265 days


#2 posted 08-15-2015 08:40 PM

My sleds eventually warp too,That’s why I don’t bother make nice ones anymore.I do try to make make them out of the best scraps of ply sometimes wooden fence sometime plywood fence.
I live south of you in so cal..

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Redoak49

1959 posts in 1455 days


#3 posted 08-15-2015 08:58 PM

I like to give my jigs a coat of shellac to help seal them and make it a bit harder for humidity to effect. The shellac dries quickly and does not take a lot of effort.

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fivecodys

582 posts in 1103 days


#4 posted 08-15-2015 08:58 PM

I forgot to mention that I used 1/2” ply for the base of the sled. Maybe I should have used 3/4”?

-- Chem, Central California

View kaerlighedsbamsen's profile

kaerlighedsbamsen

1177 posts in 1180 days


#5 posted 08-15-2015 08:59 PM

Humidity have changed. If you keep the sled on the saw the upper side will tend to have larger difference in moisture than the bottom and the tension thereby created will warp the wood. Hang it on the wall and it will probably straighten itself out (if it was straight and dry when you made it)

Hope this was usefull?

-- "Do or Do not. There is no try." - Yoda

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fivecodys

582 posts in 1103 days


#6 posted 08-15-2015 09:07 PM



Humidity have changed. If you keep the sled on the saw the upper side will tend to have larger difference in moisture than the bottom and the tension thereby created will warp the wood. Hang it on the wall and it will probably straighten itself out (if it was straight and dry when you made it)

Hope this was usefull?

- kaerlighedsbamsen


-- Chem, Central California

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fivecodys

582 posts in 1103 days


#7 posted 08-15-2015 09:08 PM

Thank you all for the comments. I just went out to the garage/shop and removed the sled from the saw top and set it aside to see what happens.

Many thanks,

-- Chem, Central California

View rwe2156's profile

rwe2156

2198 posts in 948 days


#8 posted 08-15-2015 11:24 PM

Take the fence off and check for flatness.

I’ll be that’s where your issue is.

Use quarter sawn material for fences.

-- Everything is a prototype thats why its one of a kind!!

View gfadvm's profile

gfadvm

14940 posts in 2157 days


#9 posted 08-16-2015 12:28 AM

Mine is also made from 1/2” Baltic Birch ply and no warping issues. Storing it on the saw may allow the top surface to absorb moisture/give up moisture while the side on the table cannot. This is a recipe for warpage.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

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fivecodys

582 posts in 1103 days


#10 posted 09-13-2015 12:36 AM

Hi Guys!
The new sled is finished.
Here it is. http://lumberjocks.com/projects/181682

-- Chem, Central California

View Heisinberg's profile

Heisinberg

40 posts in 1066 days


#11 posted 10-04-2015 04:17 PM

Try MDF. Works for me and no warping. http://lumberjocks.com/projects/126305

-- "I've still got things left to do." – Walter White

View Ghidrah's profile

Ghidrah

667 posts in 689 days


#12 posted 10-04-2015 08:43 PM

I made my sled base out of 1/2” ply too, MDO. I made it in early 09 and it has remained true to date. I did coat the front fence but didn’t coat the base or the rear fence. I also don’t let it sit on the TS while either are not it use. My sled sits in its own rack with 360 air flow.
1. I’m thinking a couple 3 things; it may be possible the base has warped some due to one side being cooler and or warmer than the other.
2. Another possibility is if it sat for some time, (days maybe weeks) with something sitting under the left side the base would try to relax around the object and because it is do close to the blade track the right dropped … maybe.
3. Both of the above.

-- I meant to do that!

View BurlyBob's profile

BurlyBob

3695 posts in 1732 days


#13 posted 10-05-2015 04:09 AM

I’m kicking the idea of using Melamine. what do you think about that idea!

View fivecodys's profile

fivecodys

582 posts in 1103 days


#14 posted 10-05-2015 04:27 AM


I m kicking the idea of using Melamine. what do you think about that idea!

- BurlyBob


The very first sled I built was made of melamine. It was actually material that was meant to be used as shelving.
It was fashioned after the panel cutting sled that Norm Abrams made on TNYW.
I worked alright. I sold the saw I built it for and gave it the fella who bought it.

I really liked the one Nick Ferry built https://www.youtube.com/watch?v=ZtwK9X8o1Gw

-- Chem, Central California

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dbw

143 posts in 1104 days


#15 posted 10-05-2015 11:44 AM

I made mine from 1/2” ply from Lowe’s. The left side warped so much I had to re-make it. I made the replacement using 1/2” Baltic birch from Rockler. No finish on either one. No issues so far. I also store mine sitting flat on the TS. I’m waiting for the right hand side to do the same.

-- measure 3 times, cut once

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