Wood Filler??

[AlistairM]

The situation is that I need to fill in a couple of splits and cracks in my small boat. I had a quick chat with a very nice guy from Blakes Paints who said I needed a coloured wood filler and suggested something like Brummer Stoppper single Pack (think thats how its spelt).

My question is do I need specific marine wood filler or can the local B&Q obilge. Its a varnished twelve ft boat that will be launched and retrieved and stored ashore between each trip. The cracks are not very big one on the transom that the previous filler is coming out of and two small ones on the centreboard casing.

Thanks

 

[andrewbodenham]

Any filler you use should be flexible and remain flexible over time. The cracks you refer to will open and close with changes in the moisture content of the wood, maybe quite dramatically. If the boat is now very dry and you fill the cracks with a hard stopping like Brummer then when the wood gets damp and tries to swell the crack will probably grow. A flexible goo, on the other hand, will be squeezed out of the crack.
You need something which skins over so that it can be painted or varnished, but remains relatively soft and elastic. I've used one part polysulphide sealants for this sort of job with some success, but others may know of better alternatives. You're not likely to pick up anything suitable in B&Q - try a good builders merchant, hardware wholesaler, or search online.
Ultimately you should be looking to address the cause of the cracking and replace the defective parts with new wood. Fillers are only ever a temporary repair measure.
DO NOT USE SILICONE MASTIC as this will contaminate the wood and make paint / varnish / glue impossible. It has no use in boatbuiding.

 

[alan006]

I have to agree silicon is no good for repairing cracks on boats, best left for bathroom fitters. If they are small cracks an easy solution is to make up a paste using sawdust from the same type of wood that contains the crack mixed up in cascamite wood glue. I think this is a fairly long established solution.
Alan

 

[cliffordpope]

In my experience the cascemite mix comes out considerably darker than the source wood of the sawdust. I'd use the lightest colour you can get, and the finest, literally, dust, otherwise the individual grains of sawdust are highlighted..

 

[canalcruiser]

Never use silicon.as said mix sawdust with glue as a filler works very well.Better than ready made filler which never seemed to match the colour.

 

[Grajan]

Linseed oil based putty is one of the best products for this problem as the oil "feeds" the timber and helps to keep the filler in place and is pretty flexible it can be tinted with ordinary timber stain to achieve the correct colour or if the splits are very fine, timber dust in linseed oil will be enough to stem the ingress of water until the plank takes up, another old favourite used to be Seccomastic but colour could be an issue
Another trick for sealing leaking
clinker boats was to submerge a destructable bag containing sawdust and wood flour under the keel which, when burst, would float upwards getting caught in the lands, swell and reduce the amount of water coming into the boat until the planks took up
The problem with filling splits in timber with glue & additives is that you only compound the issue as, when the boat is immersed, the planks swell and encourage the split to run further
Transom splits above the water can be routed out and a spline fitted and either "doublers" or a replacement section of plank would be the best way of reducing the amount of baling out you have to do!!

 

[canalcruiser]

Thats exactly what i use!Ive managed to fill a soft area around a fitting (the wood was damaged by the bronze fitting)It was just on but more under the waterline.The putty held for several month untill i could come out and fix it
Most people dont want a "brown or white putty"or what ever colour you make it.Thats why i use glue and saw dust,im not sure it would continue to tear?

It dose depend on the damage! I had a day fisher boat given to me and that had two planks well below the water line which had 90cmsx1cm split which had been repared with silikon,not only that but the fisherman(hobby) had contined to go well offshore with it! i changed the planks.

 

[oldfrank]

Just epoxy up the cracks and go sailing. OF