motor stringers for barellback 19 build

[Zed]

dear all
i am a new member here and not familiar how this web site works... sooo..
I took on project to build a barellback 19 wooden speed boat ...
and so far i have completed frames and transome part of build...
next stage is a Motor stringers
plan calls for 13 foot 5 1/4 inch long overall
width is 2 inch and there i have my problem
plan also calls for 3/8 ply to be applied to one side....
and my question is why is this necessary......????
why not just make motor stringers thicker 9.53 mm thicker and make whole tickness 60.3 mm all one piece ????
any thoughts are appriciated
many thanks
Big Zed

[Bob Vic]

Welcome to the CAWPBA and the BB, Big Zed. My 2 bobs worth.... I would be very reluctant to change the spec on plans. The designer will have carefully considered the required strength and nominated the timber sections required. However, there are always options. I suspect that the plans are from the USA where timber sizes and availability will be different to Australia. You should be able to locally source meranti and Douglas Fir in the sizes mentioned. The 3/8 marine ply applied to one side will be for additional strength to give the bearer more strength. If the 2" thickness is a problem, simply add 3/8" marine ply to both sides to achieve the thickness required. Good luck with the project.

[Zed]

thank you Bob Vic.. i do appreciate your help in this matter
yes plans are from USA and it is all different as size and timber availability is concerned... (more like confusing at this time)...I am still to learn flexibility in boat building..... THANK YOU

[WoodRay]

Hi Zed. Welcome aboard. If you get a chance post up some pictures which will spark extra interest with our members. We also have a website and Facebook page.
http://www.cawpba.com
http://www.facebook.com/groups/1600804660142521
If you need assistance with operating either let me know.
Good luck wit your build.

[Alan]

Hi Zed, I think Bobs on the money, the only time I have added ply it has been to cover up 60 years of drilling. That said it does however add strength so that's a bonus.