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Issues with rotting wood and hull Mark 0

PostPosted: Mon Jul 17, 2017 1:07 pm
by benllben
I have recently purchased a Mark 0 Tophat 25, the wooden hull variety, but have recently discovered a concerning amount of wood rot. The worst of which appears to be a spot the size of a 50c coin on the hull where a bolt remains after one of the strip of woods running down the hull have detached. The wood is very soft and falls apart easily when touching it. There are a few other areas where the strips are detaching, and some where they are cracking. The bottom of the bulkheads in the bilge are also very soft and rotted, however this only affects the lower portions so perhaps so wood penetrating epoxy designed for rotted wood may help with that?

I am unsure as to what should be done about the strips of wood and the hull. Would something like the penetrating epoxy be enough, and if not, what are the other options. The boat is currently moored at lake macquarie and i do not plan to sail out of the lake until it is fixed and safe. The boat also does not have a working motor, and even if it did, i could not afford to haul the boat out considering the cost of the bond at the marina.

Any advice would be greatly appreciated!

Re: Issues with rotting wood and hull Mark 0

PostPosted: Mon Jul 17, 2017 9:05 pm
by benllben
Afters speaking to a very helpful person from pittwater, i think the plan is to haul the boat out in about 2 months and scrape out all the soft wood from the hull and use the west system wood preserver. From there, the remaining gap will be filled with a thickened epoxy and faired before painting. New ribs can be sistered alongside of the original, and the rot in the bottom sections of the bilge bulkheads can receive a similar treatment to the hull, although some extra timber might be substituted for the thickened epoxy if its a large section.

Does anyone see a problem with this approach of fixing the rotting wood?

Re: Issues with rotting wood and hull Mark 0

PostPosted: Tue Jul 18, 2017 8:41 am
by Shaun
Welcome to the forum.
Unfortunately I have no idea how what to with the problems you've described. Even as a carpenter, shipwright type of work is another world.
I have received good advice from Boat-Craft NSW over the phone, when calling them to order epoxy. They have specialised products to repair timber boats & would be well worth looking into. They also have booklets on various repairs you can buy.
Some of the Wooden-Boat forums would have some good advice.
And if you have a slipway nearby that specialises in timber boats (we have one at Port Macquarie), those places are a goldmine of good advice.
All the best,
cheers
Shaun

Re: Issues with rotting wood and hull Mark 0

PostPosted: Tue Jul 18, 2017 8:41 pm
by benllben
Thank you Shaun.

Unfortunately i live in Penrith, so that is 2 hours south west of lake Macquarie.
I will have a look around at those places suggested and see if they can be of any help.

Re: Issues with rotting wood and hull Mark 0

PostPosted: Thu Jul 27, 2017 8:31 pm
by Stevensea
"Does anyone see a problem with this approach of fixing the rotting wood?"

Hi Ben, just found this post. I wouldn't use just epoxy. If you can get it supper dry, dig out as much soft wood as you can, then soak in epoxy wood preservativ. Then epoxy glue small bits of wood, like a patch work quilt. And bug any gaps with epoxy mixed with corse saw dust. The saw dust will add strength kind of like how fiboglass works.

When you get all of the cavity cleaned out and filled with the small patches of wood and sawdust, give it all a good grind with a small hand grinder with sanding discs and if you can get a hold of a small belt sander called a 'power file" (black and decker have cheap ones) Mikita does good long lasting ones.

When you have it all nice and happy, it's time to go to work with some glass cloth and epoxy resin. You could use epoxy made into a fearing compound or 'bog' now to round all the corners, this will help with getting the glass cloth to sit flat without leaving air bubbles. I often keep working the class as it sets, just to get it all sitting flat, modded against all serfises. ( sorry about the spelling )

I know that's probably not what you wanted to read. But trust me, it's not as bit a job as it sounds. It's really important to build up some careful layers of fibre strength back into there. the rot probably haven't got past the first layer of wood. It most likely stopped at the resorcinol glue.

Let us know how you get of and please show me a photo when you have dug the rot out.

All the best, Steven.

Re: Issues with rotting wood and hull Mark 0

PostPosted: Fri Jul 28, 2017 10:46 am
by benllben
Thank you Steven, That is exactly what i wanted to hear actually. It is great having another point of view, and it doesn't sound like to much more additional work.

Re: Issues with rotting wood and hull Mark 0

PostPosted: Fri Jul 28, 2017 3:58 pm
by bearmcnally
hi Guys
Regarding the ribs ,you can remove them and laminate new ones and fit the new ones back in where the old ones went.
or you could sister rib but this really only done on planked boats due to plank movement . As your Top Hat is molded so removal shouldn't be an issue.

Bear

Re: Issues with rotting wood and hull Mark 0

PostPosted: Fri Jul 28, 2017 8:01 pm
by Troppo
Hi benllben, epoxy is your friend. Amazing stuff. How much of the rotting wood you remove is up to you. If the wood is not load bearing, even very soft spongy wood can be soaked and hardens up amazingly. The problem can be that the epoxy does not evenly soak in so can be hard to tell just how strong the bit is. So, you can take out more of the soft wood and replace with bits of new wood which you use the epoxy to glue in. Makes it stronger.

Epoxy plus sawdust or other powders you can buy makes for good fill. Smooth powders in the epoxy can be easily faired.

With any repairs, as has been mentioned, you can lay some fibreglass cloth on top and paint it with epoxy to strengthen it up amazingly.

As I said, epoxy is your friend. Very versatile and as you get to use it and learn about it, you will find you can do amazing repair jobs.

Have fun.

troppo

Re: Issues with rotting wood and hull Mark 0

PostPosted: Fri Jul 28, 2017 8:38 pm
by Stevensea
Just in case anyone doesn't know. Avoid getting the epoxy into any open cuts or grazes. That's how the really bad epoxy allergies get started. If your gloves brake and you get it all over your fingers ( and you will!) you can clean it of with one of the pumice based products from Bunnings. Vinegar gets it out of your hair. I like to use barrier cream as my first defence.