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Re: UK Zip Build

Posted: Mon Mar 05, 2018 9:11 am
by 283
Use screws, mostly for clamping/assembly.

Make sure you set them back far enough so they are in the way when you start fairing.

Re: UK Zip Build

Posted: Mon Mar 05, 2018 9:18 am
by sproggy
Thanks, Mike. Presumably screws vertically through the breasthook into the top of the stem?

Re: UK Zip Build

Posted: Mon Mar 05, 2018 10:28 am
by joshuab
sproggy wrote:Thanks, Mike. Presumably screws vertically through the breasthook into the top of the stem?


I had the same questions when doing mine, what you suggest is what i did, a couple screws down through into the to of the stem

Re: UK Zip Build

Posted: Mon Mar 05, 2018 10:43 am
by sproggy
Thanks - makes sense to hold it together while the epoxy sets if nothing else.

Re: UK Zip Build

Posted: Mon Mar 05, 2018 10:44 am
by hoodman
Once the planking is installed that joint will be more than strong enough. I think it's mentioned in BBWP somewhere briefly.

Re: UK Zip Build

Posted: Mon Mar 05, 2018 8:46 pm
by BarnacleMike
For my part, I did not, and would not, run screws downward into the plywood end grain. I’d use epoxy only. I just don’t see how screws could be of any real benefit in that particular application. I have no regrets whatsoever about not using screws for this.

Re: UK Zip Build

Posted: Thu Mar 29, 2018 6:35 am
by sproggy
Well I wrote quite a long post, saved it as a draft while I did some work, then came back, finished it and submitted it and......it's disappeared :( So the brief version:

Frames now complete, dry assembled. Gussets are boring! I'm looking at a stretch of 11" to get the motor installed behind the rear cockpit without losing the standard sized Zip twin cockpits but I'll be making structural changes to compensate as the Zip doesn't have enough frames as standard to cope with a stretch.

Top motor choice is the Yamaha F25. I'd like a bit more power but 25hp is as much as I've found in a twin cylinder, 4-stroke outboard and the height of a triple means there's no chance of one fitting under the rear deck - I'm pushing my luck with a twin.

Next steps - reassemble all the frames with epoxy; source straight, stable timber for the build form; clear large, boat-shaped workspace in garage.

Re: UK Zip Build

Posted: Thu Mar 29, 2018 9:22 am
by hoodman
sproggy wrote:Gussets are boring!


That's funny.

Re: UK Zip Build

Posted: Thu Mar 29, 2018 12:11 pm
by DSR
Hi Sproggy,

The work on your Zip is looking great so far. I really like how the transom turned out, nicely done!

I also really like your drive concept (but I've always been a fan of thinking outside the box :D ).I'll be following along and I can't wait to see it in action.

Thanks,
Dave

Re: UK Zip Build

Posted: Thu Mar 29, 2018 6:25 pm
by Mr Hot Rod
I'm a bit late to the party, but here's a link to a thread which might be of interest :


Hope this helps !
____________________
Paul Kane
Kane Custom Boats Ltd.
Chelsea, Quebec

Building the Glen-L Hot Rod : http://www.kanecustomboats.com
Glen-L Hot Rod build thread
Kane Custom Boats YouTube channel
Glen-L Boat Video Directory

Re: UK Zip Build

Posted: Fri Mar 30, 2018 12:24 am
by sproggy
Thanks for that, Paul - really interesting and very close to what I'm intending to do. The main difference is I want 4-stroke rather than 2-stroke and that usually comes with a through-prop exhaust so I think I can add tricky exhaust routing to tricky cooling routing. Unless I just run an external exhaust like a conventional inboard but that might run quite hot, as well as louder.

I'll study the links later when I have more time. Mechanical issues aside, I think my main challenge is height - the rear deck on a Zip is very low and I'm keen to keep the engine covered.

Ian

Re: UK Zip Build

Posted: Thu Apr 05, 2018 4:51 am
by sproggy
I'm about to order timber for the keel, chines and sheer. My usual supplier isn't offering me the lengths I need in white oak, particularly for the 13' keel which I really don't want to have to scarf. I've contacted another supplier and they're pushing me towards yellow cedar, suggesting it's a far superior structural boatbuilding timber to the khaya that I originally asked them for.

http://www.stonesmarinetimber.com/produ ... cedar.html

Has anyone any experience of working with yellow cedar? There are boatyards using it in the UK for very high end boats so it can't be all bad and from them I can see that it glues (laminates) well. Also I gather Paul Gartside uses it quite extensively. But it's not been mentioned much on here as far as I can find which surprises me as it come from your side of the Atlantic. Price isn't my main consideration for the timber but I'm told it's half the price of western red cedar and an even smaller fraction of the price of khaya. Sounds a little bit too good to be true....

Re: UK Zip Build

Posted: Thu Apr 05, 2018 5:13 am
by hoodman
Sounds like a good option to me. Although, dint be afraid of scarfing, it's really totally acceptable.

Re: UK Zip Build

Posted: Thu Apr 05, 2018 5:23 am
by sproggy
My concern with scarfing the keel is that my motor will be bolted directly to it. Or at least the 'lower leg' will be. And I don't want to introduce even the slightest weakness anywhere near that point. I know epoxy is supposed to be stronger than the wood but....you know....just in case.

Re: UK Zip Build

Posted: Thu Apr 05, 2018 5:31 am
by hoodman
Consider laminating your keel on the inside with 1/4 ply if it's not specified in the plans. That would give you some more peaccce of mind.