Thread: My new hobby.

Hi Marc,
I see lots of work ahead, but all very doable. Sealing a clinker hull is guaranteed to generate lots of discussion and varied opinions / advice.

Polsulfide 2 pack is not available in Australia to my knowledge. I did once find reference to a product in the glazing trade a few years ago but I suggest we are stuck with single pack products.

The are a many who will say you should not epoxy the hull but if you do - a few thoughts.
Epoxy can be used to repair the planks. If they are timber (as distinct from ply) and are splitting around he nails, I would suggest glass as well. In applying all this epoxy, you will stick the planks together. Then when they try to move, as timber does, they will just split instead (unless they are ply). So each plank would then need to be glassed anyway. The sealant can then be used to seal the seams.

However, you mentioned using the sealant before the epoxy. I have not done this but it may have merit. It would stop the planks getting stuck together and then maybe glass would not be needed.
Then why use the epoxy at all except for repairs. I'll let others discuss this.

As to the sealants available, in my experience you get to choose between polyurethanes such as Sikaflex and MS (modified silicone) Polymers such as Bostick and Fixtech.

For what it is worth, my next project after the next one (?) is a skiboat very similar to yours and the plan at this stage is to epoxy and glass the planks and then use Fixtech Deckflex 100 on the seams. The project after that is a putt putt with ply planks and the treatment will be the same minus the glass.

Cheers, Mark

And all that is about the outside. I don't see any use for epoxy inside except for repairs. Just a good quality paint.
I have traditionally used epoxy enamels.
I once used Aquacote about 10 years ago. Very hard and flexible but impossible to keep a wet edge. However I have it on very good authority that those problems have been fixed. I'll be taking a good look at it again soon. And it's made by the Bote Cote epoxy people in Brissy.

On the outside you need a paint that is hard and flexible to cope with the abrasion on sandy / muddy beaches or river banks. So a 2 pack polyurethane (or AquaCote) would be best.

Mark

Interesting

The old thing is all timber and not ply that's what attracted me to it. The only damage to the timber is 2 planks with slight cracks in them. Keeping in mind I have almost no clue what I am doing here my theory was to as stated use a pollysulfide to seal the joints then use a epoxy with a wetting agent to seal the boat then dependant on how it looked either paint it or put a clear coat on it.

Do you think I may be better off sealing with polly then just painting / varnishing on the outside ?

The motor that came with it is a ford 292 y block with a dry sump and is in an unknown condition although the PO stated it should be ok. That is a lot of HP for this little boat and leaves little room for the family. do you think if I went to a lower HP maybe a diesel that it would be a little better due to less flex in the hull from lower HP ? Or is the flex just from being on the water ?


Marc

Hi Marcuse
If you don't have any major structural issues with the hull I would be tempted to do you a simple renovation at least initially. You could seal the hull as you intend then deal with any minor issues whilst you prep and paint or varnish and then get her on the water and enjoy.
After using the boat for a while you could then decide if further development (and cash) is necessary.
Good luck
Bagman

You can't 'glass a traditionally riveted lapstrake hull. Lots of reasons it doesn't work, you'll just have to trust me. There's little need for epoxy on this boat, except maybe to restore fastener holes.

Are you sure it's all timber and not plywood planked? It would be unusual for timber planks on a powerboat.

If the planks are cracked, you really can't fix then if they're solid timber. The usual choice is to cut the plank back to known good material, scarf in a repair section and rivet it back down. You could use a butt block instead of a scarf, but this isn't as elegant a solution, though maybe easier for some.

Usually on these puppies the hood ends are full of rot and under the engine, the planking/frames or structural element oil soaked. No goo in a tube will fix this, the planks have to be replaced and the laps restored so the sealant can stick. Planking, especially solid wood, has a life span and when it's shot, it's shot and there's really nothing you can do to save it, except park it in a museum for static display, with it's original planking intact. Once it starts to split around fasteners, sometimes you can refasten and use different hole locations to avoid the splits. This is often just a stop gap measure to get a few more years out of an old gal. Plank replacement, particularly garboard and bottom planks is a typical and common job on a power lapstrake. Usually the old plank can be removed, used as a template for the replacement, the replacement cut and fitted, then the next plank is yank off and the process started over.

Par

Yes all timber ply only on the deck. Your are right about the oil but this was only recent problem when the PO cut the lines to the oil tank I have started the process of getting the bulk of the oil out . The inside of the boat is varnished so the ingress is minimal if there is such a thing. The splits are above the water line and by the look are not around the rivets but I will have to check to be sure.

As far far as rot goes I have had a fair look over it and can't see any at all but if you tell me what a hood end is I will have a much closer look there.

From what I have been told it has spent 10 - 15 years I a shed in Yamba before the guy I bought it off put it in his shed and filled it full of oil.


On a side note the more I think about it I want to get rid of the big V8 do you think a boat like this will still plane with a 20 to 25 hp engine on it ?

Bagman
you you might have a point to its a fine line between a full mega dollar restoration and throwing a few bucks at an old lady for a good time.


Thanks
Marc