# Running knotty cedar through planer?



## ADHDan (Aug 17, 2012)

A few months ago I made a cedar chest entirely from Home Depot cull bin cedar - the kind that tends to be very knotty with one rough face (for aesthetics I think). It was a fun project, with one annoyance: it took forever to sand the panels smooth, with one pass with the belt sander and several with the ROS. But considering I made a chest for around $30, I considered it a victory (the final product is in my project pictures).

I still have a stash of that cedar and I'm going to use it to make a similar chest for a friend, but now I have a planer to work with (DW734). My question is: how terrible would it be to run this wood through my planer? I have a friendly relationship with the guy at the Home Depot contractor desk, and when I asked him he said that since the cedar is kiln dried it should be ok to plane, knots and all. But I'm very hesitant and would love a second opinion.


----------



## Dal300 (Aug 4, 2011)

For cedar or soft wood with knots, I always try to stabilize the knots with epoxy before hand. I use 5 minute epoxy and wait two days to plane it, but it works pretty well.

If the knots are tight when you get the wood, the chances are it won't be when it acclimates completely.


----------



## MonteCristo (May 29, 2012)

I've planed thousands of feet of knotty cedar without much of a problem. Occasionally a knot will become dislodged so you should watch for that and clear the debris right away. Knots are typically pretty darn hard, even with soft woods like cedar, so expect that to take its toll on the planer blades. IE they won't stay sharp as long as if the wood were clear. Light cuts are also a good idea here.


----------



## rrww (Aug 12, 2012)

I have had good luck with running ERC through the planer if the knots are tight to start with. The cedar is soft and planes easy, besides the knots. I usually don't go under 3/4". If they are loose to start with and you want them do what Dallas said.


----------



## bondogaposis (Dec 18, 2011)

For a soft wood cedar knots are really hard. You can plane it no problem but I would stabilize any loose knots w/ epoxy before planing and as others mentioned, light cuts are best.


----------



## ADHDan (Aug 17, 2012)

Thanks for the tips. The cedar is 3/4 to start, and I'm a little wary of planing knotty wood thinner than that (even with epoxy).

I did have another idea, though. The cedar boards I'm working with are mostly 1×4 or 1×6. I think these are narrow enough that I could essentially face joint them on the table saw in two passes - raise the blade half way up, run one face, then flip end for end to get the other face. For safety, in addition to my riving knife I would use a taller auxillary fence, and put featherboards on both the infeed and outfeed side (since there's no cutoff coming through the outfeed). I also would use a customized pushblock to keep my hand well away from the blade - something like the resawing pushblock shown in this thread http://www.woodworkingtalk.com/f2/resawing-table-saw-9392/.

Thoughts?


----------



## BinghamtonEd (Nov 30, 2011)

Dan, check out the cedar chest in my projects. It is ERC, but the concept is the same. I made the new top and ran the boards through my DW734 without a single problem. Like others have said, light cuts. I did not epoxy the knots beforehand.


----------



## ADHDan (Aug 17, 2012)

That does provide some comfort. I'm leaning towards doing some test runs on the planer (I'll glue in really loose knots), and if it seems to work well I'll go that route. Definitely would be the easiest option, and safer than face-jointing on the table saw. My planer blades are pretty new and leave a glass-smooth finish, so I'd barely have to do any finish sanding.

I assume that I should plane the boards individually, not in glued up panel sections - right? It would be nice to plane wider sections, to better ensure a uniform face in case of small shifts during glue up. But I'm pretty sure it would be a bad idea to run wide, knotty, glued boards through the planer. Plus I use biscuits for vertical alignment, which should be sufficient.

The things I do to make up for my lack of a drum sander…

Quick follow up - how exactly do you stabilize knots with epoxy? Thanks again!


----------



## BinghamtonEd (Nov 30, 2011)

I usually glue up a couple boards, then send them through the planer. Makes for quicker work. Just be sure to get the squeeze out off first (I wait an hr or two after glue up, then use a scraper I cut from an old hand saw blade). I used to use biscuits for aligning panels, but I find it quicker, easier, and with better results to use cauls instead. My cauls are just 2" square lengths of maple wrapped in wax paper.

To stabilize with epoxy, just mix the epoxy and work it into the knot with a putty knife or something similar. Just a heads up, depending on how much epoxy you have to press in there, it could take a day ro two for it to fully cure, even when using the 5-minute epoxies.


----------



## ADHDan (Aug 17, 2012)

Thanks for the explanation on epoxy - I've never used it before. I assume you just sand/scrape any surface residue, and after that it doesn't do anything bad to planer blades?

As for the cauls, did you do anything to shape them, or do you just use naturally bowed 2×2s? I definitely will give that a try, it seems like a massive time-saver over cutting a ton of biscuit slots.

I plan to rest my panels on H-style pipe clamps for glue-up, with alternating top/bottom bar clamps in between. With that setup, I assume I should put wax paper on the top and bottom of the panel, and clamp top/bottom cauls mirror-image at regular intervals - yes?

Thanks again for all of your tips; I don't have a lot of experience gluing up panels, so I really appreciate your advice.


----------



## BinghamtonEd (Nov 30, 2011)

I know some people shape/bow their cauls to make sure they have good pressure in the middle, however I personally just use straight cauls. I suppose if you want, a couple swipes of the hand plane focused towards the ends would work. I've found that as long as you've prepped the boards well, and are not trying to force things to be flat at the time of glue up, but instead just trying to keep them aligned, the straight cauls work fine. I put one set at either end of the panel, and depending on length, maybe one or two sets somewhere in the middle.

Instead of putting wax paper right on the panel, just wrap a piece around each caul and put a piece or two of masking tape around it to hold it on. That way when you're gluing up you're not worrying about it. You're right about alternating the clamps. You may want to put some wax paper over the pipes of the clamps. The first time I did a panel, I used black coated pipes clamps, and some of the black coating ran into the boards.

Just get all the clamps set up ahead of time, put your boards in, tighten them down just enough so they're pushed together, then put the cauls on semi-loose, then tighten your pipe clamps and then caul clamps.

I'm sure there are other ways people here do it, I've just found (in my limited experience of maybe 10 panels) that this works the best for me.


----------



## ADHDan (Aug 17, 2012)

Perfect explanation. Thanks!


----------



## ADHDan (Aug 17, 2012)

I have a bunch of naturally (and symmetrically) bowed 2×4s - if I rip them in half, would that produce acceptable cauls?


----------



## BinghamtonEd (Nov 30, 2011)

I don't see why not. You just don't want an excessive bow in the cauls to the point where you have to apply a ton of pressure to get them flat.


----------



## JoeinGa (Nov 26, 2012)

I tried the wax paper trick on my pipe clamps several times and found it easier to just run a strip of blue painters masking tape on each of the pipe clamps. On 3/4" pipe, I find the 1" wide tape is the perfect size. I first tried 1/2" wide but had to run 2 strips on each clamp to catch all the drippage. 
After unclamping the project I strip the tape off and re-tape again with the next clamp job.


----------



## ADHDan (Aug 17, 2012)

Good call on the masking tape. Thanks!


----------

