I have a big job coming up where I need to make quite a few thick shelves and other components. I would like to know if the Freeborn lock miter set (PC-28-020) will work when joining veneered MDF to a solid wood edge. I can’t miter fold as I want to create an offset joint to allow 1/16” of solid wood to be in front of the veneer, after assembly, to help protect it from damage. The MDF will have the tongue and the solid will have the groove. I have the shaper and groover set-up down, but I am wondering if I am going to run into problems machining and assembling with the MDF.

Thank you for any advice or suggestions you can offer.

Mark

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You can setup any lock miter for the projection your looking for. Its not a function of the tool but rather your fence setup. We run lock miters quite a bit. Once you get your head around the setup they are no big deal. There is a good setting jig out there though Im not sure if it will run on the freeborn set you state but some quick googling will likely land you on the jig. I just set them up flat on the shaper as we dont have the jig.

Thank you Mark!

I have my head wrapped around the set-up and the machining of the joint, but I’m concerned about the material… namely the MDF.

I have heard that the lock miter setup does not work well with MDF. I’m wondering if most people are referring to the “double tongue” variety of the lock miter joint (which I guess is more common) versus the Freeborn tongue and groove version (shown above). Do you think that I will run into any problems with the MDF itself or the tongue in the MDF sliding into the groove in the hardwood? Several panels will be 96” long.

Mark

I honestly dont see any issue with the cutter your using. We lock mitered 16' faux poplar beam wraps (3 sides with a cap on top) and I have lock mitered endless jobs on mantles, timber wraps, commercial components, that required the same reveal your drawing shows (solid wood face or even a slight projection for laminate on one face) without an issue and honestly we just have a dog sh8t Freud brazed lock miter for the shaper.

I understand your concern (I overthink everything) but there's not much to it. The setup can be frustrating but once you get your head around the geometry its zip. Whoever is telling you MDF is an issue I have no idea. Dealing with the issues of MDF just are what they are. Its a material spawned buy lucifer himself. Is what it is.

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Im sure your clear that your solid wood member is going to have to be thicker than your MDF member if you want a clean meet on the short point of the miter but again, the tooling and material (in my opinion) are of zero concern. We've not lock mitered a lot of MDF simply because the jobs that typically pay for that level of setup dont run MDF but I would have zero issue if thats what the customer is spec'ing

It will work fine. The only issue will be faster dulling of the cutters. The Freeborn set's fit can be adjusted with the dado width by shimming, and it is much easier to run everything flat.

We’ve been using this for years, with a dedicated shaper and tablesaw it’s always ready since we use it almost everyday. On every 90 degree corner. All outside corner of face frame and end panel. We do ton of faux beams .You will find tons of uses when you have it always setup .

Thanks for all the help.

If I groove the solid front edge as shown above, which finishes out at 2-1/4", I would have to clamp across the long dimension which is about 16" and would require lots of big clamps.

If I groove the MDF sides, I would have to clamp across the short dimension which could be easily handled with 3" spring clamps.

Does anyone see a problem grooving the MDF? I know that I wont be able to get a sharp point where the groove meets the 45° edge of the angle, because the MDF will "tear out", but I don't think this will matter.

Your thoughts?

Mark