# Best Way to Level Mitered/Biscuited Casing Joints?



## wilschroter (Dec 17, 2016)

Been working on window casings after getting some GREAT suggestions here about how to clamp them properly (3 cheers to Jim Chestnut and his Clam Clamps pictured here). Now I'm getting really tight seams, however, I'm having a hard time lining up the two pieces to be perfectly planar.










This photo isn't a great indication of the problem, but if you look downward they look pretty good. But if you look to the side you can tell there's a slight shift in one side being a little bit high and the other side being a bit low.

Question - what trick are you guys using to keep the two pieces perfectly planar to each other? I tried clamping them down to the benchtop but that didn't work. Other ideas?


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## Phil32 (Aug 31, 2018)

Assuming the placement of the biscuits control the alignment of the planar faces, you should check to see that the biscuit cuts reference the correct planar faces.


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## Axis39 (Jul 3, 2019)

Table salt holds glue joints in place and keeps them from sliding whilst aligning. But, to get them aligned in the first place, I really like the Kreg Face clamps, or project clamps that have two flat faces on a pair of vise grips. Visegrip probably makes them as well.

Here's a link to the current versions., mine are the older version.

You can also use any other clamp with two flat cauls.


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## Bill_Steele (Aug 29, 2013)

I use a biscuit to keep them aligned. Cut the slot while referencing off the back of the casing. If you need, cut a thin piece of stock that will cover the "valley" on the back and give your joiner a flat reference.

+1 for the Clam clamps-I have 2 of them and they work great!


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## wilschroter (Dec 17, 2016)

Do you guys think that the biscuit could be the problem? I'm not entirely sure how to modify the biscuit joiner (DeWalt current model) if it's off by a degree or so. I didn't think the biscuit was quite tight enough to drive the entire joint off plane.


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## Think0075 (Feb 25, 2019)

If the biscuit is keeping the two pieces from alignjng, have you considered sanding the biscuit down so it is thinner, this will give you more play in the joint and allow you to clamp it up while it's flush. The biscuit will still swell with glue and give you plenty of strength. Alternatively you could make one of the biscuit slots slightly bigger to allow for more play in the joint so it can clamped flush.


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## wilschroter (Dec 17, 2016)

Do do you guys always clamp your casings or do they somehow just magically align perfectly in a biscuit glue up?


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## Axis39 (Jul 3, 2019)

> Do you guys think that the biscuit could be the problem? I m not entirely sure how to modify the biscuit joiner (DeWalt current model) if it s off by a degree or so. I didn t think the biscuit was quite tight enough to drive the entire joint off plane.
> 
> - wilschroter


Get the biscuit wet with glue, let it swell slightly, but not so soft it falls apart when you tap it into place.

*Edit* I think I may have misread your reply… Usually when i use biscuits and the final surfaces are not co-planar, it is because I either mis-cut the hole, or the biscuit is loose and doesn't grip well enough to hold things tight. I cannot imagine a biscuit that's too tight pushing things out of place… Unless it's really too big and swells one side? But, then again, the holes need to be cut at the same depth….


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## Phil32 (Aug 31, 2018)

This discussion argues for a dry assembly of every biscuit joint before applying glue.


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## Jared_S (Jul 6, 2018)

I've never found the dewalt biscuit joiner tight enough in tolerance to leave perfect coplaner miters in prefinished stock.


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## wilschroter (Dec 17, 2016)

@Jared_S so it sounds like the problem is the biscuit joiner in this case. Hm. I'm having a hard time figuring out how to account for that.

Should the biscuits be tight enough in a dry fit that they hold the two pieces snug? Maybe mine are either too tight or too loose? I'm using DeWalt biscuits with the DeWalt joiner.


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## Bill_Steele (Aug 29, 2013)

I have the DeWalt joiner and the joint is tight enough that the biscuit holds the joint together. When I put glue in the joint then I often need to use clamps to help pull the joint together. The biscuits should not be loose-you should be able to slide them slightly left or right.

Perhaps your technique and/or the joiner is off? I put biscuits in all my window casing miter joints and the profiles line up very well-no sanding or adjustment required-so I think this is a viable approach. Obviously you still need to glue and clamp the joint. The biscuit helps keep the joint aligned and may add little strength.

I suggest you practice making biscuit joints until you can get a joint that you are happy with. Experiment and analyze the results. Maybe your biscuit joiner needs a tune-up or adjustment? Does your joiner rock even a little when you reference the base from a flat surface? I found a video where a guy makes an adjustment to his DeWalt joiner to help him get both halves of the joint to line up. Search for videos on how to use a biscuit joiner. Watch several of them to get different perspectives.

Plane some wood so that it is all exactly the same thickness. Find a flat surface to work from-if you don't have a flat work surface then get a piece of MDF, plywood, or melamine that you can use. You really need a flat surface-if there is dust or debris under the stock being cut or the base of the joiner that can screw up the joint. Try referencing the base of the joiner and the stock being cut from the same flat work surface.

Once you are able to get a joint that lines up-when referencing the cut from the base of the joiner-then move on to practicing with the fence.

Maybe you can get a flush joint by hotmelt gluing or supergluing a flat piece of "guide" stock that spans both halves of the joint to keep the halves on the same plane? This would be temporary until the glue dries and then pry that "guide" off before nailing the casing in place.

Good luck.


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