Mark's C21

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mmachonis
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Mark's C21

Post by mmachonis » Thu Jul 30, 2015 10:40 am

Jacque,

My name is Mark Machonis. We have spoken together on the phone several times. I hope you are feeling well.

I received my kit this week. I am about to get started. I have a few questions based on Reading Sam Devlin's book.

In his book, he indicates that he builds using a female jig with the boat right side up to start. He indicated that by doing so, you can keep your structure in proper alignment throughout the stitching/filleting process. Then set a few main permanent frames and longitudinal supports, then flip the boat and complete the exterior. I kind of agree with him. It seems to me that if the structure is upside down, there is no way, or it is more difficult to measure that the frames are in proper alignment with the hull. In addition, the frames can be fastened to the hull structure with temporary screws without damaging the completed exterior. Assuming a male jig is used, the exterior is completed first and then the boat is flipped so temporary frames set with screws would damage the completed outside. My thought, based on Mr Devlin's premise, is to make a cradle that keeps the water line level. Stitch the hull structure together, Fillet and Tape the inside of the hull using spreader bars and temporarily place frames to maintain the alignment in the cradle. Glass the inside. Set the longitudinal supports and frames on the interior and then flip the boat. Fillet, Glass and paint the exterior and flip it back over to finish the inside.

Am I overthinking this? Am I misunderstanding something? What are the advantages and disadvantages to using either method?

Mark



Fuzz
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Re: Mark's C21

Post by Fuzz » Thu Jul 30, 2015 11:11 am

Hey Mark welcome to the group!
I have no experience with building your boat or one of the boats here built on a jig. I did build an OD-18 and here is what I have learned. The best way to get it done is to follow the plan that is laid out for you. Others have done it and it works. Other builders have their methods and I am sure they work for them but if you go your own way with one of the plans here I think you may be sailing off into uncharted waters. Sometimes that is a lot of fun and sometimes not so much :lol: Before building my dory I had built 4 other boats from 18 to 36 feet so I did have a little experience. I still found following the tried and true plan was the best way of doing things. Just my two cents worth.
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Re: Mark's C21

Post by mmachonis » Thu Jul 30, 2015 11:15 am

Fuzz,

So how do you assure the alignment on the Male Jig? Devlin explains that once your boat is twisted, it can never be untwisted.

Mark

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Re: Mark's C21

Post by mmachonis » Thu Jul 30, 2015 11:17 am

Fuzz,

By the way, thanks for the advice. I truly appreciate it! I am a sponge trying to absorb all the knowledge I can!

Mark

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Re: Mark's C21

Post by Fuzz » Thu Jul 30, 2015 1:07 pm

Mark,
Like I said I have not built one of the plans from here that use the male jig. You will find plenty of boats built that way and many tips on how to keep them straight. Read the building tutorials and they explain it very well. I am sure one of the guys with much more knowledge will chime in also. What I do know is if you follow the plans and the advise you will receive here you will end up with a good boat. Devlin and others design good boats and their ways work but the plans here work also and they work best if followed.
I have built three male mold boats using C-Flex. It is a totally different method with different materials. They have survived 20 years of commercial fishing in Alaska so I have to say the method works also. As they say there are many different ways to skin a cat.
Keep asking questions you will get answers here.
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Re: Mark's C21

Post by mmachonis » Thu Jul 30, 2015 3:28 pm

Jacque and Fuzz

I re-read the Self-Aligning Jig Tutorial and it makes more sense to me now. With the Stations Frames and longitudinal supports in place the alignment should be correct. Using the motorwell knees as the last station supports in the stern provides the correct transom angle.

I'm on board.

Mark

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Re: Mark's C21

Post by mmachonis » Thu Jul 30, 2015 3:49 pm

Jacque and Fuzz,

The sentence below is from the Self-Aligning Jig Tutorial:

I hope that you saw on the plans that we measure from a specific mold face, forward or stern side. Align that face with the line, not the other one. Center the mold on the strongbacks.

What does "we measure from a specific mold face, forward or stern side" mean?

I realize that the mold needs to sit on one side of the line marked on the StrongBack. The origin is at the bow in your diagram. So when you say "stern side", I assume the the frame will be on the far side of the line from the origin toward the stern. Is this correct?

I just want to be clear.

Thanks.

Mark

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Re: Mark's C21

Post by TomW1 » Thu Jul 30, 2015 4:29 pm

Mark you are correct. When it shows to align at the stern side of the mold use the stern side. When it shows the forward side use the forward side. Some boat plans use all forward or all stern others mix them. There will be one diagram in the plans that shows how the molds line up.

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

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Re: Mark's C21

Post by Fuzz » Thu Jul 30, 2015 4:31 pm

Mark,
I do not have a set of plans here at this time so I will try to go fro memory. I could be wrong so keep that in mind. There will be one mold and will be lets call it the master. All measurements will be taken from the face of it. This will be shown on the plans. I hope this makes sense to you. The plans show it pretty clearly.
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Re: Mark's C21

Post by Fuzz » Thu Jul 30, 2015 4:33 pm

I just saw Tom's post and he is totally correct and said it better than me.
Fuzz

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