Prototype build of ELLIE

[Bob Abell 2Participant @bobabell2]

Last of the stringers glued in position…..A very pleasing stage

Note the spreader between the saw cut bends……..It is holding the bends in equal symmetry while the glue sets. The spreader has a half way mark which lines up with the datum centre line

We don`t want any banana boats at this stage!

Bob

[Paul TParticipant @pault84577]

Hello Bob

It looks nice and square but what is the white substance around the new piece.

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

It's only an extra coat of PVA

I think we need a few vertical braces, the bendy bit is rather weak?

Bob

[Nigel EdwardsParticipant @nigeledwards16506]

This is a great thread to see how the design and plans are made in the first place and the back and forth plan changes between workshop and office.. although im new to this hobby and only have 1 scratch build to my name I want a set of these plans also, Bob and Paul your a credit to everyone on here.. Nigel

[Bob Abell 2Participant @bobabell2]

Thank you, Nigel

We hope you do decide to make Paul's model and post pictures of your progress as the model develops

I know you will make a superb job of it, having seen your Kingfisher trawler build!

Bob

[Peter FitnessParticipant @peterfitness34857]

I like the idea of the breast hook, as it would simplify things considerably. I also like the peg board idea, so I will have to file both ideas in my memory bank for future reference.

Peter.

[Paul TParticipant @pault84577]

The next major stage of Bobs build is the skinning of the hull and it is the part of the construction process that I thought about the most.

All experienced builders will know how easy it can be for little errors to creep in during the building of the frame and that it is only when the skin is fitted that these little errors manifest themselves and result in the pre-designed skin not fitting correctly.

I was not concerned about an experienced builders ability to build accurately but I did think hard about beginners and the possibility of small mistakes being made on the frame.

One way of overcoming any error was to not detail any templates for the skin but instead to explain the process of making a card template of the frame and producing a 'bespoke' set of skin parts. In this way the beginner not only learns a new skill but they also 'build out' any mistake that might have been made.

For a builder of Bobs skills the taking and transferring of templates will be a walk in the park but for a beginner it will be a valuable lesson and impart some confidence in their abilities.

Paul

[Bob Abell 2Participant @bobabell2]

Thank you, Peter

You could always use a thickish board and a bag of 2" nails!

Bob

[Bob Abell 2Participant @bobabell2]

Shop floor to Slave Driver…..

Sheeting a slab sided hull is quite easy and I would prefer to use 3mm ply, but the bows are not looking a Walk in the Park to my liking?……Not forgetting the built in tolerance!

Even 1,6mm doesn't like flexing against the grain!

Just wondering, for a compound curve….Which way should the grain actually run?……D.O. to advise?

The first job at the moment is to sand out any lumps and bumps on the frame

I still think a few braces, up front will make sheeting a little easier, they would prevent the thin ply from concaving

Bob

[Paul TParticipant @pault84577]

Seneca to shop floor

In a compound curve the grain of the ply should follow the end of the curve on the basis that this point is where the most stress will be. However the cross grain nature of commercially available plywood precludes its ability to form tight curves and so it might be necessary to notch the rear face of the ply to aid the bending or to use a double layer of lite ply in these locations.

[Bob Abell 2Participant @bobabell2]

Thanks Seneca……….Who`s Seneca?

Just tried a piece of 1,6mm ply and it will go round but will need a very strong method of keeping it there, while the glue dries! Don`t think elastic bands would be any good either

We need a method of weakening the ply back face, by scoring etc….or even prebending?

I would suggest making the top and side skins in one piece, as trying the flex a local curvy skin would be impossible

How Paul coped with 4mm ply is a mystery?

Bob……………………Pulling out all the stops!

[Dave MilbournParticipant @davemilbourn48782]

Bob

No sheet material will go around a compound curve but I don't see any of those on Ellie. Neither do I feel it would be necessary to add any futher bracing.1.5mm ply is plenty thick enough and once it is bent you will be surprised how stiff it has become. It can be bent easily in the steam from a kettle. Just make sure you remove the lid or it will keep switching itself off!

Ref grain direction, it's easier to cut the side and bottom panels in one long piece i.e. with the grain running fore and aft, but the natural curve of the hull is in the other direction. If you were using sheet balsa then you'd run the grain from chine to gunwale and chine to keel and make butt-joints between the pieces of sheeting. This isn't that easy with thin ply however. My recommendation would be to use single pieces for each panel – cut to a card template – with the grain running bow to stern and bending as required. 3mm ply would be a) difficult to work and b) very heavy.

Dave M

BTW Seneca was a Roman philiospher of the Stoic school – essentially they believed in gritting their teeth in the face of adversity.

Edited By Dave Milbourn on 12/08/2013 08:50:18

[Bob Abell 2Participant @bobabell2]

Hi Paul

Just tried 1mm ply and the difference is refreshing!……….What a difference, twenty thou` makes!

What about 1mm then?

I think it`ll be better for the Newbies?

Bob

[Bob Abell 2Participant @bobabell2]

Hello Dave

I`ve never steamed plywood, as I imagine it would melt the glue!……..Just an fashioned idea from the days of Fish glue!

I will try a piece just out of interest

What do you think of the 1mm idea?

Bob

[Dave MilbournParticipant @davemilbourn48782]

1mm ply? Where do you buy that? Please check with a vernier or micrometer, Bob.
DM

[LARRY WHETTONParticipant @larrywhetton68737]

Good morning ,

Have a look here,…… **LINK** ……

                           birch ply .4mm ..8mm ,, avable so get on with it ,

                used both on swordsman and gaurdsman  go with grain  

 bends easy , double were needed ………….email www.  avonplywood .co.uk……

                            Larry..

Edited By LARRY WHETTON on 12/08/2013 09:54:08

[Bob Abell 2Participant @bobabell2]

There yer go, Dave!

If we go to Haydock, next week, I`ll get some in!

Bob

[Bob Abell 2Participant @bobabell2]

Here we go boys!……Don`t know how I do it for the money!

Tested a piece of 1.6 ply for flexibility, against the grain and with a sensible force, achieved about 6mm bend….Not bad but would be difficult to glue in position and clamp it somehow

So I put the ply in a frying pan and boiled it for about 5 mins

It was quite pliable, if not somewhat distorted, as can be seen in the photo below

BTW…..Those are not my hands!

So I think 1.6mm ply should be ok, since 1mm ply is not readily available?

Gladys in the canteen

[Dave MilbournParticipant @davemilbourn48782]

Posted by LARRY WHETTON on 12/08/2013 09:40:35:

Good morning ,

Have a look here,…… **LINK** ……

Larry
The link doesn't work but, assuming it belongs to Avonplywood, I had a look. They have only 0.8mm and 1.5mm in birch ply (plus thicker). There's no 1.0mm, which was my question. I still haven't found any source for that thickness although I have to admit that Bob's caliper is unlikely to be that far out! On the basis that 1mm plywood isn't readily available I would opt for 1.5mm over 0.8mm. My 28" Shamrock used 0.8mm and it was a bit borderline on the "starved horse" look in places. Most decent model suppliers stock 1.5mm birch ply e.g, SLEC.

Bob
Once you've steamed and bent the ply, hold it until it gets cool and it will retain enough of the curve for glueing. Hint: only steam the side on the outside of the required curve. THere are no sharp bends on this hull now (I gather that the area below the breasthook ahead of frame 1 will be made of block material). I would recommend Deluxe Materials' Super-Phatic as an adhesive to hold the skins down at the ends; standard Aliphatic glue is fine for the long stringers etc.

Dave M

[Bob Abell 2Participant @bobabell2]

Thanks Dave

Didn't think of that method…..

Using 1.5mm ply

Steam it on the inside face for about 5 minutes

Bend it in position and then retain it with kicky bands or even rope and leave it to set

Then glue it

Will do

Bob

[Dave MilbournParticipant @davemilbourn48782]

No – steam the outside face. It will expand more than the opposite face and bend the ply away from the heated side. Five minutes might not be required – just test it as you steam it.
DM

[Bob Abell 2Participant @bobabell2]

Ok, Dave….Thanks a lot

Bob

[LARRY WHETTONParticipant @larrywhetton68737]

Hello Dave sorry link did not work , Avon plywood is the link , based in Keynsham ,

yes the town that made Horace Batchlor the pools man…

Bob / you may try chain drill through bow area and ply and thread a wire tie glue and when dry resin inside , tidy up with p38 filler . block the bottom of keel ,

just a thought, used to use this on bow fronted bar counters,……….

cheers Larry…

[Bob Abell 2Participant @bobabell2]

Thanks Larry

I've not up to that stage yet, but holes and wire is a good idea?

Bob

[Paul TParticipant @pault84577]

Bob

A belated answer to your question regarding bending 4mm ply, I used marine ply and cut notches on inside face of the curve, pulled the bend with a rachet strap and glued with commercial waterproof PVA then used countersunk screws to make sure the joints wouldnt pop.

Paul

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