There comes a time when rubbing strake needs replacing

[Refueler]

My 1970's boat ... Sunrider 25 ... has over last number of years had its teak rubbing strake repaired / refixed / filled ... but it was obvious that these actions were only delaying the inevitable.

The list of work needed :

Foam backed vinyl Headlining replace - I have Van lining with spray adhesive already for the job. Forecabin already done. Main cabin still to do.

Teak rubbing strake rotted and now fastenings no longer holding it in place.

Wood trim covering cabin 'furniture' to GRP joints to replace

New sprayhood - mainsail cover - dodgers.

As with old boats - the list can be as long as you still have paper to write on - or you can accept its an old boat and select accordingly.

The main area of concern is that Rubbing Strake. I approached a local yard. Discussed whether to replace the teak with 'wood' or to accept a rubber based alternative. They wanted to replace with steamed Oak - which seems a bit OTT in my mind ... but of course Teak is not so easily obtained or as good quality as the 1970's.
I am considering doing the job myself - but realistic in realising my work would likely not be as good as the yards. To steam 8m lengths of wood as well is not a task to take on lightly.

Interested to read of anybody who has taken on such a job (older GRP boats particularly) ...

Here is the strake when it was still in good condition ! But shows clearly its relation to level of deck ... it does cover the Hull to Deck joint....

One of the repairs ... before shaping and staining to blend in ... can be seen that surrounding teak is 'soft' and soon to fail - which in fact it has now ...

It would appear that the teak strake was held by screws into the GRP as there are no nuts or retention parts on inside of hull. This fact is also one of the reasons I am considering rubber replacement instead. Rubber fendering would be easier to fix without steaming by same method.

Always interested to hear of others solutions ...

 

[Refueler]

......

One guy actually suggested I do away with the strake and fill / smooth the area ..... as we all use fenders anyway ...

 

[tillergirl]

Doubt you would need to steam it. Got to have plenty of fastenings (and a chum to help). Does it really need to be replaced. A section can be replaced using a pair of scarfs.

 

[Daydream believer]

I would use air dried Iroko. Not kiln dried, as the grain in kiln dried is harsher & more liable to splitting . You would have no problem bending if you had help holding and fixing from the sharpest bend & working towards the shallowest bend end
But always investigate scarfing in sections, as suggested by Tillergirl above, first.

 

[WoodyP]

You can get rubber strip extrusions made up to fit over the existing strakes. The Kingfisher Owners had some made up to replace the original rubber strip strakes. Expensive though.

 

[Refueler]

The strake has a serious bend IN and UP as it passes midships .... even the Yard guy when he looked last year talked about steaming it.

There are two scarfs in the original and of course - these are the first areas that failed. Boat is early 70's - so its lasted well !

I would like wood ... but think I may end up with rubber type .....

My issue now is to find it as eBay / online costs + shipping are putting just the material at over 1000 quid ...

 

[Wansworth]

Scarf up the length of wood needed for a whole rubbing band but only half the thickness.Fastento hull.Then scarf up another length maybe pre rounded edges this is then screwed to existing new bit

 

[johnlilley]

Cold bending will almost certainly work if the section is somewhere around 50mm x 25 mm or less. Fastenings every 7 inches or so bending into position gradually. Looking at the photo, I don't think the stake is teak though. Not instantly recognisable but certainly looks a bit degraded. Iroko, mahogany, sapele will all be fine. Oak is a bit stiff to bend cold.

 

[Rappey]

How about plastic wood ? Would be very easy to fit and it's so realistic nowadays .
Here's a site with prices Planks & Profiles Trade
Looks good ? I would like to see it for real.

 

[PlankWalker]

If the teak rubbing strake is no worse than the section your showing,
I would be inclined to refasten with machine screws and re plug, what you've got.
I've never known teak to rot, all mine, and I've got a lot of it, is from 1936, and in good nick.

 

[William_H]

I helped a friend replace rubbing strakes on his 22ft GRP sail boat. He got wood from local supplier. Not sure what. Scarf joined it to give a section of suitable length 7m aprox. In his case thickness was about 15mm but a groove was cut down the middle to accommodate a GRP to hull join. Bending around the hull did not seem to be a problem although it was straight in vertical plane. Job was attached using 5mm ss screws. A hole was drilled through wood and GRP. (about 4mm) then outer hole in wood enlarged to 5mm and a countersunk cut. Then a 5mm tap was run into the GRP and finally a screw run in with a battery drill and phillips head bit. So needed 5 battery powered reversable drills. A team of people to hand up drills and to support the wood (on ladders) Both sides done in about 90 minutes. He might fit nuts on the inside of the screws in areas of load but generally not necessary. Do fill the existing holes when you remove old rubbing strake. ol'will

 

[Refueler]

How about plastic wood ? Would be very easy to fit and it's so realistic nowadays .
Here's a site with prices Planks & Profiles Trade
Looks good ? I would like to see it for real.

That would be ideal - but I'm not in UK to take advantage of it. I don't think Latvia has such product.

 

[Refueler]

Found quite a few Plastic Wood production in Latvia online ... but they all produce Terrace Decking. None produce a square profile needed for this job.

I've decided that I'll have a friend visit who owns a Wood Mill ... they process trees into sections for passing onto companies such as Kureks who produce boards / PAR etc. I'm hoping that he can advise and identify supply of suitable wood that can bend and mount without steaming etc. TBH - I'm quite happy to accept any wood ... PIne ... Birch ... whatever is available and can be formed.

 

[Refueler]

Cold bending will almost certainly work if the section is somewhere around 50mm x 25 mm or less. Fastenings every 7 inches or so bending into position gradually. Looking at the photo, I don't think the stake is teak though. Not instantly recognisable but certainly looks a bit degraded. Iroko, mahogany, sapele will all be fine. Oak is a bit stiff to bend cold.

The wood has been stained each year until it really started to fail ... that's where the 'red mahogany' look came from. The previous owner stained it to a darker type. I thought it was too dark so I chose a mid range 'Mahogany' style.

Lets be honest .... freshwater is no friend of Teak and boat since arriving in Latvia (2007) has been on a freshwater mooring .... the teak was already many years old by time boat came here.

Over the last 5 years - its been a battle to keep the strake against the hull. Each time screws or pressure applied - the rotten wood just splintered or crushed. Its a job that I have been putting off year after year ....
Finally the strake has 'won' .... on the stbd side where I scarfed in the small piece - strake has finally come away for about 2m ... far too much and wood rotten to try fixing again.

With the spinal injury and then breaking my big toe .... I'm stuck ... no sailing this season. The question is now whether get some friends round to drop mast and get boat lifted out ... place on my hard base and once my foot is OK (spine was welded in surgery) .... set to before winter takes hold.

 

[Refueler]

Measured the strake .... 60mm wide, 30mm depth, in 2m sections scarfed along hull. Transom is very long scarf at centre at 2.54m

If I repeat same in local wood ... the steamer would be quite a simple short affair .... basically a large waste pipe with 'boiler' spout one end and partially blanked other end .... about 3m long.

~2m long sections can be easily handled and should not require such brute force of more than 2 people to install before it cools.

I have considered laminating .... taking thin sheet and then creating curved laminated strakes ... fanciful idea but not so crazy as it first sounds.

 

[Refueler]

Pal due here today who has Timber business ..... will see what he says ..... (guy who is in earlier photo washing off the hull in Swedish Archipelago ... we had a marvelous 10 days cruise).

I'm wondering whether I can get away with replacing sections rather than the whole ? Considering that original is in 3 scarfed sections along the hull and two short scarfed on transom.

 

[Refueler]

OK ... 8m of planed profile wood will be delivered in sections to replace part of one side.

He looked at both sides and asked why replace portside - its still serviceable. Sand - stain and leave alone.

Stbd side - rotten scarf joint has given up with aft section grain splitting as rot has got in. That's about a 2m section. Going fwd from that joint about 3m to next scarf joint - wood is showing signs of near EoL .. so we plan to remove those two sections - leaving the fwd section in place. That's a length of about 5.2m all told. That leaves enough to replace the 2.6m transom if needed, or keep as spare wood.

He reckons the wood he will supply can be cold bent

Our intention is that we lift boat about 1 month from now before winter cuts in .. I should be more fit to work .. we'll both do the job. I have good hard concrete area to stand the boat - see earlier photo ... and all the electric / tools necessary.
We are hoping that the original screw fastenings will work ... with perhaps an odd additional Luckily the sections to replace are not the serious bow curved areas !!

 

[Refueler]

What is it they say about best laid plans ??

OK - all change ... Pavilosta will now get the boat at start of 2023 season ... I will most likely still be in Physio for my spine.

They now have a list :

Replace in Blue material

Dodgers
Mainsail cover
Sprayhood

While that's going on ... the entire rubbing strake both sides and transom will be removed and new fitted. The old is weathered teak 60 x 30mm .... new will be Air Dried Larch - (not their choice - they offered Oak ... but my pal with the timber company has a good supply of Larch available) ... but will be 65 x 35mm. It will then cover any marks etc ....

Before any 'experts' start on about Larch being xxx ...... take note ... this is Krasnoyarsk Larch - completely different to UK / USA etc. Larch .... see :

Siberian larch (Larix sibirica)
Siberian larch is very resistant and durable wood. It is the only representative of conifers, which is added to the hardwood category and in hardness is comparable to oak.
Larch is common in almost all over the territory of Russia, as well as in most of Europe, Japan, US and Canadian territory, but particularly valuable is only the larch grown in Siberia (lat. Larix sibirca). Since the climate in Europe, Japan and North America are much milder, the European, Japanese and North American larch wood is more loose and at best is comparable to a simple pine. Annuals rings for such larch is about 3-5 mm wide, while the Siberian larch, they may be even narrower than 0.5 mm.
Siberian Larch is common mainly in taiga forests of the Krasnoyarsk and Irkutsk regions and also less in mountainous Altai region and the Far East. As these regions have very blunt and rather dry climate (average 65%) with extreme temperature changes (in summer up to + 40 ° C, and in winter down to – 60 ° C), larch grows very slowly and grows very dense.
Larch species’ dendrological particularities in combination with the harsh climate also creates this high-quality wood, which is comparable to the precious wood and hardwood. The most valuable types of Siberian larch wood is considered to be from Krasnoyarsk area of central and southern parts, or from Irkutsk area, because in theess areas has a long growing larch, little branchy, dense and relatively easy to be supplied from the felling areas to saw mills.
Siberian larch’s stems (logs) are quite smooth, and with a very low shrinkage factor, branch crown has a conical form. It’s height reaches 45-60 meters and a stem’s diameter may reach about 1.5 to 2.5 meters. It reaches its maturity when is about 300-400 years old. Larch average life expectancy is 500-700 years. But in some regions there are found even 1000 years old trees. Thanks to its majestic appearance, excellent properties and resistance to the harsh Siberian climate, in Siberia it is seen as a symbol of eternity and majesty.

So as he said - its suitable for the jo0b and costs far less than hard to get Oak here ...

 

[Rappey]

My boat had mahogany . At around 35 years old I discovered it looked OK on the surface but it had rotten internally by water getting in between the hull and the mahogany.
I would suggest a roll of of butyl tape on the hull before attaching the wood to prevent the water ingress.

 

[Refueler]

My boat had mahogany . At around 35 years old I discovered it looked OK on the surface but it had rotten internally by water getting in between the hull and the mahogany.
I would suggest a roll of of butyl tape on the hull before attaching the wood to prevent the water ingress.

Same with mine .... looked ok on outside - but the inside was basically disintegrating. Led to the scarf joints failing.

Many don't realise that quite a few hardwoods actually rot with freshwater, but are resistant to salt water. Rain gets behind and it rots.
Not only on boats - if hardwood surrounds on house windows are not treated well - it happens there ... the usual corner joints failing.

I plan to 'soak' the new wood before fitting.......