Gunwale Rubber 50mm Alkathene On Bounty Boats.

[DaveT]

I intend to replace sections of the gunwale rubber on my Bounty 34 , locks and hire boaters having taken their toll over the years.   It is the black 50mm MDPE/Alkathene as used on many Bounty designs.I read an article on the process a few years ago  but cannot find it.  I would welcome any advice/help on the best way to do this , particularly from any member who has done this job.

I think that I am aware of the basics including the cutting and steaming  necessary but any links to articles will be helpful. On the one article  I  did find it refers to a   '  tool to spread the pipe ,' any ideas on this would be useful.  Also is any grade or supplier of pipe  better than any other?

Regards

DaveT

[Ray]

Sounds like quite a job, sorry I don't have the answers but it would be interesting if you could keep us up to date on progress and the process once you begin.

[Vaughan]

It needs 5 men, standing on a length of staging beside the boat, which has been hauled out of the water. One man to hold the end up, one man to hit it hard with a large wooden mallet and a third man further along its length to hold it up in line.

The other two men are for standing there and yelling at it!

[Vaughan]

Seriously though, this is not a job for the faint - hearted and is probably the job I like least, in boat maintenance. You are much better to have it done by a boatyard as they are equipped. They also have the "spreading tool", which are all hand made affairs. Only short repairs can be attempted with the boat on the water and it is best on the hard outside as there is usually not enough room beside the boat, when it is in a shed. Someone has recently had the bright idea of steaming it first, like a plank, but that is great if you happen to have a steam chest!

The other problem is that this rubber also hides the flange joint between the hull and deck mouldings. When the rubber gets damaged, the flange often gets broken off inside, so there is nothing left for the rubber to bend onto. This is a very awkward repair to do in GRP and is also best done by a boatyard.

I have seen Simpsons in Stalham doing it recently. They are very good at it.

[DaveT]

Hi  Vaughan,  Thanks for the words of caution....  think I will be able to find the watching grunters,  always an abundance of them I've found!

There is only what really amounts to severe cosmetic damage to the rubber and I only intend to replace 2 sections on each corner of the transom about a metre each so they wrap round and join the original on a straight but joint. These  I will cover with stainless tubing sections . I have had a dry run with the split stainless tube and it looks really good and a snug fit.

The flange I think has not been damaged, certainly there is no evidence to that effect from inside the boat, it seems to be bolted through at about 20 cm centres. I have not cut away any of the rubber so don't really know what is the profile . Can you help with that ? If I know the profile I might be able to think of other alternatives.   From what I can see it looks like a rounded C section .

I would ideally take the boat to Simpsons but based in France it's a bit of a problem, and would like to try myself in the first instance. The boat is out of the water over winter and when I will be working on it.

Regards, Dave T

 

[Vaughan]

2 hours ago, DaveT said:

The flange I think has not been damaged, certainly there is no evidence to that effect from inside the boat, it seems to be bolted through at about 20 cm centres. I have not cut away any of the rubber so don't really know what is the profile . Can you help with that ? If I know the profile I might be able to think of other alternatives.   From what I can see it looks like a rounded C section .

I thought the best way to describe this was with a drawing, but didn't realise how difficult it was to draw! Hope this makes sense  :

 

Fig.(1) shows the Bounty system of joining the two moulds. For clarity (don't laugh) I have left out the deck beams, toe-rail inserts and other things involved in the actual build. Bounty were building single level bath tubs and so this was a way of simply joining the deck and superstructure a bit like putting a lid on a saucepan. I know one of their original designers and so I know this was also a way of being able to fit out the interior into the hull first, and putting on the superstructure afterwards. This was supposed to be cheaper and easier in mass production but I am not sure that it was, in practice.

The disadvantages can (I hope) be seen in the drawing : 

1/.The bulbous lip sticking out of the side of the boat is weak and very vulnerable to damage, especially on a hire boat. Once this has been broken off, the plastic pipe has nothing left to grip on to.

2/. The profile shape shows that there is effectively a rain gutter all along the side of the boat under the toe rails, which is always full of water, unless someone thinks about drain holes. If there is damage, then the water can run straight into the boat, down the inside linings and all over the mattresses.

 

Fig (2) shows the more normal method, where the deck mould overlaps the hull on the outside. There is sometimes a sandwich between the two, especially around the flare of the bow. The bolts which secure the two moulds together are also used to secure the rubbing strakes and the strakes themselves add a great deal of strength to the join. It can also be seen that even after minor damage, it is unlikely that rain water can get into the boat. Panelling on the inside in the cabins is removable, to give access to the fixing bolts, for damage repairs.

As you are in France, you will find that any of the LeBoat hire bases will be able to help you as they have several types of boat built in this way. Locaboat (a French company) also use exactly the same system on some of their boats. 

[OldBerkshireBoy]

This is mine where a previous owner has cut a section out of the transom, note the horrid screws which will be covered once I have nice shiny stainless end caps made.

Was told that the rubber is no longer available but perhaps the chap didn`t fancy the job for which I can`t say I blame him.  Looks heavy and unflexiable to me.

 

 

 

[Regulo]

11 hours ago, Vaughan said:

The other problem is that this rubber also hides the flange joint between the hull and deck mouldings. When the rubber gets damaged, the flange often gets broken off inside, so there is nothing left for the rubber to bend onto.

Oh, yes.

[NorfolkNog]

I'm pretty sure that Royalls described this in one of their blogs. I'm sure that they steamed it first. As they dealt with wooden boats they no doubt had a steam chest. Is it possible to construct one I wonder? 

[FairTmiddlin]

Howard go to You Tube and search for Acorn to Arabella.

The URL You need is https://www.youtube.com/watch?v=lLi4V9S9gnI

This will show you how they built their steambox.

Believe me the whole thing is worth a watch from the first video. These two guys are incredible

[ChrisB]

I met a chap at Beale Park and he showed me a pic of his Steam Box which he had constructed from scafold boards and two or three adapted steam generators which were B&Q own label wallpaper removers.

[grendel]

the one for my model boats is just a wallpaper steamer and a length of 1 1/2" drain pipe.

[grendel]

the one we used on Royal tudor was just an L shaped pipe, stopped up at the short end, the other end angled upward and a propane torch heating a pool of water at the bend.