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Mold Making

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  • Mold Making

    Here's interesting thing's about mold making from McKee Craft.

    I looked at the link and agree, great info and better yet...good PICS.

    A few pointers: When building flat surfaces, boxes, panels, and such. Build using the 11/16 (AKA 3/4" Luan) and then contact cement on shiny formica, some like to cover the entire sheet with formica first and them cut the shape and screw the mold together.

    For Radiuses I like steel balls of various sizes. 1/2" is gonna be the best fit of all, giving you a 1/4" raidus. Have a buddy to weld a 6-8" long handle of the same material to it and you're ready to go with a filet tool that can't be held wrong, and it can be pushed or pulled. As a bonus, if you let it get hardend material on it a propane torch or your wifes oven if you're brave cleans it "Starrett makes a set of SS ball radiuses like the ones describe above.

    For outside or male radiuses either a roundover on a router or go to your favorite shape on a boat and cover the area with masking tape and a bit of wax over the tape (to be sure) and lay in a "blob" (industry tech term) of bondo with a piece of wood cut near the same shape on the blob for reinforcement. Shave each side flat and then either cut or sand one side larger than the other, without damaging the original casting on one side. This "funnels" the bondo in front of the "scred" and give a near perfect duplication. I have them from 1/8" up to 20" raduises and some very complex shapes. However I normally use my bondo casting as a templet to cut a durable one from 3/4" starboard.

    Call me if you like and I'll talk you thru any questions you may have and I'll pick up some scrap 3/4" starboard blocks to send to you for making these. FYI I make my ball spoons the same way from starboard. Hell, tell me what radius you want and I'll make you one, one afternoon. Then you can describe these things for everybody else.

    I use bondo to make my filets, I also I like to add a little resin to the bondo for third and final drag so it will be smooth and bubble free. A 4" long piece of 1/2" OD wooden dowel or PVC matching your filet for a sanding block will perfect it. FYI, the "CUZ" brand at Napa was used on my entire Freedom line

    Use a "Partall" paste wax and then it's sprayable sister product PVA to get a 100% release from the mold, surface will be a bit dull but it always releases. Buffing will bring back a great shine.

    If you are building wacky curved sufaces, forget formica. Most compound complex surfaces are bondo, primer, sanding and hardwork. Here you need to use Klegecel sheets and a couple of layers of 1-1/2 oz. glass/resin, and then IMHO 20-30 mils of Duratec E-Z Sand primer hand block sanded and a second coats with finer sandpaper (down to 800 DA wet) and finally LIGHTLY buff to a dull shine. Heavy buffing will raise the wood grain and everything else.Then the PVA release aid.

    If you have any questions let me know. I'll try and answer them on the board for everybody.


  • #2
    Good info there. Who is this guy? Is he the one on THT that was showing the new pilot house boat prototype? Is there a link to this site?

    Oakley, California


    • #3
      Yep, that's him.