Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Any Other Builds => Topic started by: manofkent on January 16, 2018, 09:47:36 AM

Title: Mantua Bruma
Post by: manofkent on January 16, 2018, 09:47:36 AM
I have had a search of the archives and found some useful info regarding Hull Planking.  I am, however, having some difficulty on visualising some of the planking on my new build Bruma. The pic shows state so far and once my left eye recovers from recent surgery (Vitrectomy) I will start the hull planking. What I am having trouble visualising is the area of lower stern aft of the Bulkhead frame carrying the prop shaft support.  Any suggestions/advice greatly appreciated.
Title: Re: Mantua Bruma
Post by: Ianlind on January 31, 2018, 06:31:46 AM
I'm thinking if you were to move this to another topic like "Beginners Start Here", you might get more lookers and therefore more chance of help.
Just my thoughts as I only found this by accident, as it's well outside the more popular topics.
Title: Re: Mantua Bruma
Post by: manofkent on January 31, 2018, 09:07:02 AM
Will try to do that, although it has been viewed 153 times.
Title: Re: Mantua Bruma
Post by: dougal99 on January 31, 2018, 11:40:11 AM
I would think that planking the stern with what looks like a very distinct curve would be quite difficult. The planks would probably need additional bulkheads to support the required curve. In this situation I have resorted to carving block balsa after terminating the planking at the last bulkhead. All my planking efforts have been scratch builds not kits so I've had no qualms going that route. You may think differently. Good luck.
Title: Re: Mantua Bruma
Post by: SailorGreg on January 31, 2018, 12:19:49 PM
That looks an interesting challenge. Clearly the prop shaft support has to end up outside the planking. Presumably Mantua expect you to stop the planking one side of the support and continue it on the other, which strikes me as both difficult and unnecessary. There isn't even anywhere to land the planks on the aft side of the support. If it was my model I would scrap that support piece, run the planking all the way to the stern and make a new support fixed to the outside of the hull when you have finished and faired the planks. Regarding planking the tight curves at the stern, how you address that depends a little on the planking material.  If it is reasonably flexible, some pre-bending between the fingers can help, or perhaps use a plank bender to nip the plank into shape. or even follow full size practice and steam the planks to get the bend in place.  Or, indeed, do as Dougal99 suggests and simply fill that last space with a block of balsa and carve to shape.

Remember - it's all part of the fun!   O0

Title: Re: Mantua Bruma
Post by: manofkent on January 31, 2018, 02:40:31 PM
Yes, you & Dougal99 have picked up on the very points that are giving me concern. Once passed the last prop shaft support the planks have to curve very sharply to clear space for the rudder and 2 props. The idea of putting a block in has already occurred to me but I am expecting a call from one of our club member who is well experienced on PoF hull construction so he can see it first hand and offer advice 'at the coal face' so to speak.  Yours and Dougal99's comments are well appreciated, thanks.
Title: Re: Mantua Bruma
Post by: barriew on February 05, 2018, 07:24:02 AM
Check out this build - no balsa blocks here!

Title: Re: Mantua Bruma
Post by: manofkent on February 05, 2018, 09:23:06 AM
I see what you have done at the stern. I was over thinking it. Nice one, thanks very much.
Title: Re: Mantua Bruma
Post by: barriew on February 06, 2018, 09:07:41 AM
Not mine! but I thought it may help. I think there are other builds on this Forum as well.

Title: Re: Mantua Bruma
Post by: manofkent on February 06, 2018, 04:03:07 PM
Very glad you posted the link.  As I progressed it seemed as if there would barely be enough clearance for the swing of the props (supplied).  I noticed in the blog that the supplied plastic props were discarded for 35mm 3 blade brass.  My kit has been supplied with 40mm Die cast 2 bladers.  I guess for display purposes, so I have taken a leaf out of the blog book and ordered a pair of 35mm that will give the extra clearance I need.
Title: Re: Mantua Bruma
Post by: Morris75 on January 03, 2019, 05:46:35 PM
I found the same problem with my Bruma,used 1/2 inch balsa at stem and stern blended into the curve to give larger ares for glueing.The lime wood in the kit is very springy and can crack if bent dry. After shaping the planks I wet the wood at the ends and formed in my fingers to get the right shape before gluing with waterproof PVA. I used thin cedar for the outer layer of planking, much easier to work and just as strong.Needs lots of patience but the result is well worthwhile, mine sails really well.
Regards Morris75
Title: Re: Mantua Bruma
Post by: manofkent on January 04, 2019, 11:46:38 AM
I did for a time consider using balsa blocks, but after engaging the little grey cells I came up with a way to plank it and get the desired shape.  I did, however, leave the prop lock nut  some 4mm clear of the end of the prop tube to get closer to the required gap between blade and hull.  As you say with yours, she does sail very well, so much so that I have to reduce max throttle or she is too fast to look right.