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Author Topic: Bilge Keels (again?!)  (Read 1243 times)

Garabaldy

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Bilge Keels (again?!)
« on: February 04, 2009, 02:50:08 AM »

Well i am getting closer to adding bilge keels to my 1:36 pacific buccaneer hull.  Im just after a rough guide as how to go about it.  Ive seen a few different ways of doing it, plastic wod and the likes.  Can anyone recommend the most suitable way for myself doing it?  The hulls 6ft long and the plans do not show bilge keels anywhere but ever model of the same class of ship i have seen has a bilg keel (on the OSV society website) so im pretty sure there is one.  I also found a picture of a similar(ish) full size ship being launched and it had bilge keels.

So, how should i go about it?  Do i use wood and cut a slit into the hull then fit in the bilge keel or do i glue the bilge keel directly onto the planked surface?  Is it easier to fit them before or after i put a layer of fibreglass tissue over the hull?

Hmm can you tell im slightly confused (a little worried too!) about doing this?

Thanks,

G

PS i have a pile of photos to upload showing my build so far but since i very cleverly corrupted my photo uploading software i cant do it very quickly.....
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derekwarner

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Re: Bilge Keels (again?!)
« Reply #1 on: February 04, 2009, 05:42:07 AM »

Gary....I think you have answered many of your own questions....in that you know quite a few options...

So if it is a planked hull...your thought of removing a slice [of plank] then inserting the bilge keel plate...then reinforcing with resin & glass tissue from the inside of the hull is a sound concept

Being a 1:36 model & with a 2000 mm long hull.. lets assume the vessel displacement could be easily 25 Kg...so a bilge keel end face could certainly take the brunt of load force reaction of hitting a submerged object

If the hull is ultimately to be glass tissue & resin coated, then a rigid plastic bilge keel material could  be suitable....[depending on the bond strength between the plastic & the resin], alternatively a wooden section bilge keel would have a very high bond strength

Either way....using the galss tissue + resin on the extremities [next to the hull] would allow you to blend a ...say 3 mm radius between the length bilge keel plate & the hull to offer great strength

Remember the bond + strength between the bilge keel & the hull is the critical area of concern....no point in having a super TOUGH bilge keel plate which if damage ripped itself from the hull

I am not a big fan of composite build with wood + plastics....followed by glass + resin........etc

Post some .jpgs with actual construction detail & I am sure other members will offer sound comments  O0 .....Derek
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Derek Warner

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Bunkerbarge

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Re: Bilge Keels (again?!)
« Reply #2 on: February 04, 2009, 08:29:00 AM »

I think you have some sound options there but my own construction is a bit of a variation.  Mine was a fibre glass hull and I made the bilge keel from wood.  I didn't want to introduce a weakness in the hull though by cutting a slot and I didn't want to stick it on the outside where it could be vulnerable.  My compromise was to make the bilge keel with tabs as part of it's shape.  These tabs were then lined up with a row of slots in the hull so the keel was very firmly attached but I didn't have the full length slot that I was concerned about.  This also gave me the option of putting resin over the tabs before covering the tabs with p38 filler.  The outside was then painted with resin to soak into the wood and seal the whole thing.
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TCC

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Re: Bilge Keels (again?!)
« Reply #3 on: February 08, 2009, 12:28:49 PM »

As the earlier lads have intimated, you are best to fix the keel to the hull with some form of supports as a keel will probably be knocked in it's lifetime. Yes, it involves pierceing the hull but the modern glues/fillers sort this out.

And keels should be straight and run parallel to the fore & aft line.

If I remember rightly, I have about 4 or 5 'tabs' [supports] on my keels, they're about  2ft in length. I made them of 2mm ply and had resin cover them and form a fillet along the joint (both sides) and then sanded it smooth.

To form the actual keel, if you can't go off the plan, mark where the keel goes, then cut some wood/plastic to a rough shape of your keel but leave enough for your tabs on the 'inside' (towards the hull) Then it's a matter of preference if you cut the keel tabs to suit the slots or vice versa. But it's trial and error. I, myself, would cut the inner part (tabs and inside shape) first as you can then fix it to the hull. I'd then do the external edge to finish it.

But take your time and do it bit by bit, keep offering the pice up and trim bits off as needed, offer it up and trim and do it like that... and then finish with sandpaper.

Then once you have formed the inner edge, and tabs, and fixed it, you can then form the shape of the actual keel.. the 'outside' edge.

Good luck, hope it helps. Remember, it's not rocket science and you can finish it any way you want (as long as it's straight. :-))
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