Hi Shaun,

Loads of work for a one off!  I like composites also it is just that cedar planking a hull only takes 2 or 3 days and is really simple. Also possibly more accurate unless used to foam shaping and avoiding the usual pitfalls.

One piece wrap works;  assuming you will be using fine twill weave and epoxy. Still you will be surprised at the weight to add with the fairing filler at 30-40grm per coat. 

Don't forget to colour pigment  the coats ! I use U pol, by the way.

Add some pics as you go.

Richard

Disaster avert! Too little epoxy midships ended with the hull in 2 halves, liberal amount of epoxy for the second attempt only to find the mark one eyeball didn't quite have everything aligned as it should (oops!). A cut and shut operation followed with a new 6th section inserted.

Now for lots of filler to cover the dents in the foam, bit more sanding then hopefully it'll be ready for a nice coat of glass.

A slow burner of a project but I'll get there in the end (hopefully!)

 

Hi Shaun, I would just get some glass onto the foam before trying to fair with filler, it will give you a firm even surface to fill and fair.  By trying to fill and sand the foam you will only end up sanding more foam from around the patches of filler.  

4 years down the line now and Alternative continues to sail well. Have often been asked about the boat when sailing; seems to be a popular design for home building. 

The only mod I have made is the fitting of a small Hitec waterproof servo (HS5086 WP) right on the rudder stock. This employs a small moulding made by Dave Creed. See picture for installation. 

Very effective and, because it is lighter than a typical rudder servo, does not have a negative effect being right on the end of the boat.  Absolutely no play because there is no linkage. BUT the achievable angle is greater. Now this is useful when using the rudder as a brake; start line for example. Needs to be allowed for in normal sailing though.

Have used this servo completely in the open on Mini 40 trimaran, but lives under the aft deck patch on Alternative.

Richard

Finally got round to giving my Alternative a refit. Main job was to re coat the hull. Never having been too pleased with the original epoxy finish. Sanded all of with 120 and proceeded to apply 3 coats XCR epoxy, wet on wet. Finishing with 120 dry followed by 400/800/1200 wet to achieve a super slippery finish. The epoxy is extremely hard and also adds strength to the cedar planking. 

The technicalities of weight are detailed, since these are vital for any one building in wood.

Hull finish (epoxy) sanded of with 120.   -10grms

3 coats XCR epoxy wet on wet.   + 60grms.   (20grms / coat) applied with roller

Flat back as described above.  -30

I have added 20grm to the boat but have a much tougher coating and have been able to sharpen the chines more. Super, super smooth hull.

Richard

Response to recent request for info on fitting Finbox and well.   Pictures show Dave Creed's Finbox bonded to well prior to setting into hull. Then a couple of shots of the assembly.  I have tried all wood and also a single all-in moulding; just too heavy.

PS. The 3 transverse beams are removed after fitting the deck.

Richard

 

 

 

Edited December 20, 20223 yr by Richard98
Typo

Thank you Richard. That’s really helpful.

Thank you Richard , didn't know DC made moldings like that !!  Should save me time in future !!

Still receiving mail from "Alternative" builders; which is great. However this posting is not Alternative specific but would be of interest to anyone considering moulding in epoxy glass.  Picked up the latest issue of Marine Modelling magazine after noting the "Radio control racing sailboats" heading; 132 pages no less!  There, on page 46, is a 4 page reprinted article that I prepared for publication some time ago. 4 pages of illustrated laminating of Graham Bantock's "Image" One metre. Which as you may know is "Ikon" moulded horizontally rather than vertically and from the same original mould.

Anyway the pics may be of value, but please be aware that tech has moved on since then. I would be happy to answer any queries regarding how I would do this currently or even just to explain anything.

Richard

Been asked a few times: what allowance I make for sanding when cutting the shadows / sections.

This is one of those questions that answers itself once the "mechanics" are appreciated. Obviously you can sand and sand; removing an unknown amount of material.

The reality is that it actually takes care of itself, just like a well set up boat going to windward.

The 10mm plank cross section obviously cannot follow the curve of the shadows / stations. The median of the plank is correct and the outsides must be +. Therefore when sanding (with a long board of course) you will, or should, be removing this + only and no more. Therefore what you have is the 3mm plank sitting on the shadows exactly.

Keep the questions coming.

Richard

 

Richard saw my reference to building an Alternative on another thread and invited me to add my piece.   It had been my intention to build a wooden Alternative,  but a set of Kris Panis mouldings turned my head.

I needed to set the hull up with the fin in the right place etc, so I built a jig.  The rest was straightforward.  I had the hull sprayed in lacquer by a local car body specialist and I got my sails from Housemartin.  Not a lot more to say ..... except that I wished that I hadn't attached the rudder servo mount until after I'd finished with the keelbox.  I needed more slender and dextrous fingers than my gnarled old hands have!  But I got there.  Maiden voyage yesterday with A Rig and happy smiling bunny!  I hope she's as fast as my dreams!

Looks good but I’d say the rig in the photo needs to be much lower in the boat. The same with the other rigs.

6 hours ago, Dave Kent said:

Looks good but I’d say the rig in the photo needs to be much lower in the boat. The same with the other rigs.

Thanks Dave.  The rig was lowered by about 7mm subsequent to the photo.  This is the maiden voyage with temporary hatch covers.

Hi Vernon - are you intending to sail your Alternative at Askern?

I’ve sailed my Alternative (56) for a few years now - any help needed just ask.

RobT

16 minutes ago, RobT said:

Hi Vernon - are you intending to sail your Alternative at Askern?

I’ve sailed my Alternative (56) for a few years now - any help needed just ask.

RobT

Hi Rob,

Thanks for the offer.  I've just joined Askern club and any advice will be gratefully received.  I've raced my old Zigzag design a few times elsewhere and enjoyed it.  I've also had a couple of guest visits to Blue Lagoon with my Marblehead so I'm sure my IOM will appear there soon.

Cheers,

Vernon