Square corners - how does amana suggest this?

[dima]

So I was looking at
http://www.amanatool.com/cncroutingdetails/rc-2252.html

One of the notes is:

To produce MDF Shaker cabinet doors use
RC-2252 and square corners with Straight Plunge #45200

I'm lost - so the big spoilboard cutter will get a round corner but then the straight bit will still leave rounded corners right?

[Gary Campbell]

Dmitriy...
Yes, you are correct. There are no square inside corners cut with a round bit. The "industry" seems to accept using a 1/8" bit for an acceptable, but almost square, 1/16" radius as a substitute for a square corner.

We have done MDF doors using a pointed roundover bit for a beaded wainscot look and used a v-bit for a bevel to the panel. This does yield a square corner, albeit on a beveled edge. Panel is recessed 1/8".

Here is a pic:

4955
Gary

[dima]

Aaah, thank you!
I guess a 1/8 corner is not so bad but I was just very confused how they had claimed to do actual straight cuts.

V bit sounds like a great idea!

[Gary Campbell]

Dmitriy...
We got that job for 3 reasons; 1) the square corners, 2)The "beaded" look and 3) because we were able to line up the beads for the door panels to the draw panels above. We also got double what the MDF production cutter in Miami charges.

They were time consuming as we used a 1/2" downshear to area clead the recess, a 90 degree Vbit for the border, a 1/8" radius pointed roundover for the beads and a 3/8 Compression to profile. We cut around 90 doors wholesale for another shop. That shop, the Architect and the Owner were all happy. We got a nice job out of it.

Here is the VCPro preview:

4956
Gary

[bob_s]

Gary
How did you, or your finish shop, seal the mdf to get a good finish on it. I have been getting decent results with a coat of Titebond II 60%, then a coat of Bin shellac sanding sealer, then 2 or more coats of my waterborn lacquer. It takes an awful lot of careful sanding, and cussing, in between each step. Is this the nature of the MDF beast, or are there only nasty solvent based solution that you pro's use?
thanks

[Gary Campbell]

Bob...
The shop that ordered them did their own finishing. They also supplied the MDF, and as I assumed, they profided a less dense version that was a lot fuzzier than the sheet I made the sample from.

They used 1 heavy coat of Clawlock, unreduced. Let dry overnite. Sanded with 180 and then a coat of 25% reduced Clawlock. Scuff sand and finish with a double wet coat of MLC Stealth Post Cat Lacquer. This was their 1st MLC job and they are happy. I can remember a lot of cursing about sanding the grooves! They had 8 hrs sanding on 60 doors and draw fronts.

I know there are a lot of other methods mentioned on this forum, but since I know that nothing is less stable to moisture changes than MDF, and because I am old and set in my ways, I NEVER under any circumstances, put a water based anything on wood. Especially MDF, which we wont even use as a product for our customers. Had this been a retail rather than wholesale job, we wouldnt have even done it.

A portion of this comes from our warrantee, which warrants our work for as long as a customer owns the product. When you get to see what happens to various finishes and construction methods over a decade or so, it changes the way you do them the next.
Gary

[jason_b]

Has anyone ever used a mortising chisel set up to get square inside corners on their Bot?