plug for 22feet boat - doubts

[fabioely]

Hi
Im going to make a skiboat 22feet, 100"wide boat.
Im just finishing the design and now I have to make the plug.
My plan is to cut (CNC) stations of 15mm MDF (Medium-density fibreboard), assemble it in a steel support and after, cover the stations with 9mm MDF.
After that, put filler, sanding, painting and start to fiberglassing the mould.
As I have no experience with this process, So I would like to hear from you some tips and previous experience to make my job easiest as possible.
Thanks in advance

[rwatson]

Not sure what you mean by "cover with 9mm MDF".

Are you going to try to use 9mm to bend over the moulds? That would seem a bit hard. Usually you use much bendier 'planking'


I found this site has some good videos on filling planked surfaces www.flexicat-tools.com

[SamSam]

Plug and mold making is not a short story. It has been discussed here many times and there is not much sense rehashing things. To get an idea of what might work best for you, and would also be quickest way to get information, would be to use the three search functions. One function (Search) will search all the forums on this site, and the other (Search This Forum) will search individual forums. There is a third, (Search This Thread), which will highlight in red the word you enter and pick out relevant posts in long winded threads that drift around to different subjects. "Boatbuilding", "Fiberglass and Composite Boat Building" and "Materials" are 3 good forums to search individually with inquiries such as "plugs", "molds", "plug building", "mold building" etc. Those will give you a general idea and maybe all you need to know. You can always ask more questions here.

[rwatson]

Originally Posted by SamSam

Plug and mold making is not a short story. It has been discussed here many times and there is not much sense rehashing things. .

Good point Sam, but a losing battle. If we only discussed things that there was no published info on, the whole site would close down.

But, having said that .... let me say this ... there is some great stuff about making moulds in those areas.

I would be happy to re-hash the concept over and over again myself, but then I find playing checkers fascinating

[gonzo]

MDF for planking is not a good idea. You need something that can be faired with planing and sanding. Steel supports are harder to work than wood.

[SamSam]

Originally Posted by rwatson

Good point Sam, but a losing battle. If we only discussed things that there was no published info on, the whole site would close down.

But, having said that .... let me say this ... there is some great stuff about making moulds in those areas.

I would be happy to re-hash the concept over and over again myself, but then I find playing checkers fascinating

You're right about discussing things but I'm a slow two finger typist who makes a lot of mistakes.

The flexi-cat tool was interesting. I usually make whatever special tools and fixtures I need and find that just as interesting and enjoyable as any of the other work.

To make a production plug and a production mold is a big, expensive project (to some) and a gamble on an unproven design. If only one boat is wanted a plug-mold-boat route is not practical. A cheap temporary mold-boat route would be better, or a straight plywood boat made directly, if that boat works to expectations and more are wanted, it can be finished to plug perfection and a mold made from that. If it doesn't work as expected, it can be modified until it does, then finished as a plug and then a mold made.

[fabioely]

hi
thanks for the responses.
my idea is planking with 9mm MDF. I have no difficult curvatures to bend the MDF. The bow of the boat has two curvatures and I would use strips to make, so I dont see problems to use 9mm MDF.
Anyway, I am searching according you mentioned in this forum. good videos in the flexicat tool site
thanks.