My wordworking so far...

[monkfish24]

Diadem's (SeaWolf 26) hatch was long overdue being repaired and we bought her witht he hatch needing replacement, or at least the woodwork being renewed.

I've dismantled it and the lateral pieces are made of a solid piece of wood which has been shaped to make a curved piece. Doing this will take too much time, a large piece of wood and will be very hard to shape in a smooth curve. A friend of mine is very good with woodworking and suggested the following method, cutting a piece of wood into thin strips and then epoxying them, using the original frame piece as a template.

I understand Cold Moulded ply boats were always done in this manner but have never seen it done and this is my first time trying this method.. So, for those who want to try the same technique's, here are a few photo's.

This shows the original piece (top) which is obviously well rotten. The pieces of wood on the end allow for the spring after the new piece is epoxied and it should hopefully be around the right curvature. It had gone soft on one end so I cut this end off and put a double length piece of wood in. The two battens are screwed into the original.

These next pictures show the middle cross member just placed on top to show how close to the original curve it is.

These haven't been epoxied yet as I'm waiting for the temp to go up a bit, the petrol generator isn't quite man enough to run a heater in the garage

 

[sarabande]

looking neat !

It's a lovely way to make a smart tiller.

 

[VO5]

Yes, nice bit of carpentry there. Will look good when finished.

 

[Twister_Ken]

Something I know little about, but wouldn't it be better to steam a piece of solid wood into the curve?

 

[monkfish24]

Not something I know about TBH, this method I think is probably far simpler than generating enough steam to do that. On the plus side, the epoxy used to glue it all prevents having to varnish it all after it's been planed and sanded.

 

[Twister_Ken]

Not something I know about TBH, this method I think is probably far simpler than generating enough steam to do that. On the plus side, the epoxy used to glue it all prevents having to varnish it all after it's been planed and sanded.

I think it'll still need to be varnished to provide UV protection. Either that, or rub in some Ambre Solaire!

PS - fairly easy to generate steam using one or more wallpaper strippers.

 

[sailorman]

you will achieve a better shape by screwing short blocks of wood with a single screw ( allows it to pivot ) onto a sheet of ply to the desired shape & cramp the strips to each block. this way will eliminate "hard" spots

 

[Lady Campanula]

Either that, or rub in some Ambre Solaire!

I've got some of that in the drawer. What Protection Factor should I use with Afrormosia?

 

[sailorman]

I've got some of that in the drawer. What Protection Factor should I use with Afrormosia?

Afromosia is already a protected species

 

[pcatterall]

I have steamed short lengths in the past ( insulated waste pipe and wallpaper steamer).
It worked ok but the timbers did tend to return slightly to their original shape when released from their clamps. This was fine for my job, as I was able to bend and screw the work to the final position, but no use for the OPs requirement. Perhaps my steaming was underdone? I imagine that going the epoxy route there would be no problems with this.

 

[Babylon]

Here's a better way to do it

OP

If you haven't glued it yet, then here's a more accurate way to do it:

1. Trace the original curve onto a piece of wood at least as thick as the width of your new lamination strips and about 4" wide, and make it long enough so can extend the curve at either end by a couple of inches.
2. Use a jig-saw or bandsaw to carefully cut to the line to make your 'former', and complete it by marking and cutting a second curve about 3" below the top curve (this will enable you to clamp square to the curve's tangent at every point).
3. Borrow as many clamps (G-clamps or F-clamps) as you can, so that you have a clamping point every 2-3 inches if possible.
4. Make up a clamping strip from say 4mm hardboard or similar, so that your clamp heads don't bruise your outermost lamination strip.
5. Rub wax on the former and the clamping strip so glue squeeze-out doesn't adhere to these.
6. Do a full dry-assembly to check everything works (and to ensure your clamps are set to exactly the right opening for the actual glue-up - you won't have time to fiddle with these later).
6. Roll or paint on the epoxy to the strip glue-surfaces and clamp.

Notes:

(i) With laminating, you don't need to allow for any spring-back, so make the curve on your template exactly how you want it.
(ii) Ensure that your strips are carefully aligned (ie no large overhangs along the edges) to reduce the amount of planing you have to do afterwards.
(iii) When it comes to planing, do one edge first and check that its true using a straight edge and square to the curved top by checking with a small square. Then use a sharp cutting-guage to mark the width off the first planed edge, and plane down to the guage-line to ensure you have a parallel width.

Hope this helps,

Babylon

 

[gordon029]

re seawolf

Hi I have a seawolf too.Its the mk 2 . I would like to see a photo of the finished product if you get a chance. Thanks

 

[sighmoon]

Something I know little about, but wouldn't it be better to steam a piece of solid wood into the curve?

Why? A laminate is stronger than solid wood.

 

[monkfish24]

Babylon, Thank you for that, unfortunatly I didn't read it till after I had started I think I will use your technique next time.

Gordon, of course, I'll be doing a few photo's all the way through. Mine is a Mk1, have you joined the seawolf and cobra owners group, under the community banner at the top of this page?

well here's the next photos, post epoxy. Probably a bit too much curve but nothing the plane and band saw won't sort out! Oh and please excuse the work boots!

The top piece you can see in the picture is the middle section, the piece I'm making is the fwd section and the aft section has very little rot thankfully!