The Way MT Boats Were Made - Information from Chip Freeman

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Anonymous

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We built the boats from the outside in. The molds were gelcoated (the finish on the boat) Then the laminate was applied and rolled (2 skins) Then the wooden brace for the floor was tied in ( more laminate) the plywood floor put in place and more laminate to tie it in. The floor had holes in several places so the foam could be shot in. the wooden transom was put in and tied with yet more laminate. That was just the hull, the deck was reinforced with (believe it or not) cardboard tubes cut in half length wise and laminated into place. I remember the process much better than I remember the dimensions.

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jack22182

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The Way MT Boats Were Made - Information from Chip Freeman
« Reply #1 on: May 26, 2004, 05:40:41 PM »
Do you remember at what point they started using the injected foam? Was it 1975 or earlier, or later? Just curious, in a couple of weeks I\'m going to start a floor replacement project.

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Anonymous

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The Way MT Boats Were Made - Information from Chip Freeman
« Reply #2 on: June 01, 2004, 07:11:37 AM »
Jack...in answer to your question...Chip said he started with MTM in 72 and at that time they were shooting foam into the floorboard...hope this helps...

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sailor61270

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The Way MT Boats Were Made - Information from Chip Freeman
« Reply #3 on: April 27, 2005, 10:00:37 PM »
I have come across one of the original molds (behind a place that manufactured carnival rides outside of Youngstown Ohio) for a Mark Tawin- the 17 foot center consol I believe, and plan on building one for myself.  I have never built a boat, but was thinking on a boston whaler type construction with the hull made first as descibed in the above post and then making a foam core to shape and lay the deck overtop of since i do not have the deck mold-  Any thoughts or suggestions would be greatly appreciated.

regards

jeff

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Anonymous

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The Way MT Boats Were Made - Information from Chip Freeman
« Reply #4 on: April 28, 2005, 07:42:01 AM »
Do you have a pic of the mold...interesting location for the find...thanks for the information....not sure if anyone else has any other molds....

john

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98-1089160674

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The Way MT Boats Were Made - Information from Chip Freeman
« Reply #5 on: April 29, 2005, 03:22:45 PM »
Another way is to make a plug off of a boat. Then the mold can be made from the plug. This is a common practice and is done all the time.

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1972vsonic

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The Way MT Boats Were Made - Information from Chip Freeman
« Reply #6 on: October 09, 2005, 12:10:15 AM »
in response to the foam question, My 72 15\' V-Sonic I/O did not have foam in the floor, I  installed it when I put in a belly tank to replace the tank that was mounted in the port side rear against the transom. By  the way, that foam is no fun to work with. It is very messy!
You\'re not paranoid, you are being watched!

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Mkb4550

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The Way MT Boats Were Made - Information from Chip Freeman
« Reply #7 on: February 16, 2009, 01:09:37 PM »
Here is a little more technical info on construction.  Reverse gel coat mold is a female made from high temp resins.  Mt molds were catalized in the 3200 degree range while the actual piece was molded in the 2800 range.  The molds had to be reenforced with steel to prevent warping.  Most builders of the time ran a batch of hulls then a batch of decks.  
the problem was that this produced a very poor match between the two.  No matter what you did the mold changes a little every time it is used.  To provide a good fit MT used numbered and matched sets.  A very heavy mold release wax was applied to the mold before the gelcoat was sprayed in place.  The layup was done in chopped fiber.  This is very short glass strands that are sprayed into place along with the resin.  Chopped fiber has a higher resin content therefore it is heavier. It also provides excellent compression strength as opposed to woven or hand layup cloth. In the event of damage a hole was localized to the area and was less likely to  produce longitudinal fractures.  The stringer system was called a double H as it resembled two Hs stacked on top of each other.  The typical builder still uses a single crossmember if any at all. i.e. Bayliner came in with entry level boats with only a partial transon connected to stringers that were only long enough to accomodate the motor mounts.  The rest of the floor was wedged into place along the hull and that was all of the strucutural rigidity they had.  At MT the stringers, thwarts, transoms and floors were laminated with heavy resin and some glass to prevent rot and bond them into place.  The stern and bow rings were placed in with backing plates and through bolted and are designed so that you can lift the entire craft using only these three points.   The deck hardware was also through bolted with backing plates but not designed to lift the entire vessel.  Most mfgs. used mass produced seats and interior bolsters.  MT built all of their own in house.  The industry average was 28oz vinyl with a fuzzy backing material.  MT used 32oz vinyl with a flat loop back.  We used to demonstrate the advantage as follows. Cut a 1 inch x 9 inch strip of each material. Soak them in water and hang over the side of the glass.  The fuzzy back material will siphon or wick the glass dry while our material stayed dry.