filling digs and dents in primed mahogany hull ,what to use

[nelsonmandela]

I am in the process of buying a boat which is fundimentally sound but out of the water and in need of substantial restoration .HOWEVER the previous owner has attacked the hull with the sanding belt in quite a few places, taken digs out of it,and then use a primer.How should the hull be filled and faired ,does any one recomend a filler that can be over painted to leave the hull smooth and sound with out any likely hood that it will fall out later or cause problems in the future with recoating /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

 

[rjp]

I used West Epoxy mixed to a suitable consistency with their microfibres for quite a nasty patch on Alysia. Needed several thin applicatoins and lots of sanding to get it fair but after painting with two coats undercoat and two coats of topcoat you would never know it was there. Still great after 1 year but how long it might last ultimately is anybody's guess. I would imagine that as long as the paint film stays intact preventing excessive moisture getting behind it then it should stay put for some time.

John

 

[nelsonmandela]

Hi John,I am reluctant to use west system on a c lassic wooden hull as I am cocerned that it seem to inflexible in comparison with the wood and I seem to recall that there is opinion out there that this in itself can lead to moisture gettiing trapped behind it. Do you think that there is anything more like a filling primer that can be used?

 

[srp]

International Interfill.

 

[Porthandbuoy]

The epoxy manufacturers seem to recommend total encapsulation. ie. inside and out. I've always thought this a bit risky as any knock, scratch or ding will allow water into the wood where accelerated rot will result.
In a recent edition of CB I read about a restoration where epoxy was applied externally and a vapour permeable coating applied internally (Burgess?). This, to me, seems a far more sensible idea.
As for filler, I find West epoxy and their Low Density filler easy to work with and sticks like you know what to the proverbial blanket.

 

[Roach1948]

I have used West Microlight www.boatpaint.co.uk . It is VERY workable and sandable as far as epoxy goes. I started with Micorfibres but its hard to apply. To fair, I used an old sail batton which I bent to the hull shape to apply the mix. It was then easily sanded by hand using sanding longs made from thin plywood and cutting up lengths of unused sanding belt connecting the ends with bulldog clips. I then discovered that it is also worth colouring each coat with a spoonfull of powder paint in order to keep a visual check on what you have re-covered, as after a while, it surprinsing how you loose track of the areas your filling once again!

 

[jhughes]

Brummers Green label stopper works well in small digs and holes, its listed as suitable for use in seawater and sands back really easily.

 

[rjp]

It's surprisingly flexible in thin layers and I'm not suggesting that you sheath the whole boat with it, just using it as a spot filler where necessary which is a totally different application. Then there is plenty of breathable surface around it so any lack of porosity wouldn't be a problem.

John

 

[EASLOOP]

P38 (autobody filler) is a favourite cosmetic surface filler. Easy to sand etc. recommended in a boat building/repair book. I have used it on my wooden sloop. For structural work I used epoxy for rebuilding some plank lands; used it after digging out chainplate bolts, filling the timber with epoxy and finally re-drilling the bolt holes. Used in a similar way to repair the galvanized floor bolt fastening holes. Used it for replacing other fastenings - drilled out conical holes, filled with epoxy, re-drilled holes and re-fastened - in effect creating an epoxy conical washer strong enough to pull the planks back into fair.
I have been doing this for a long time on my boat and she is showing no signs of plank cracking or separation from the epoxy. Also used it on my wooden mast. Made up a 'putty' of epoxy and sawdust and repaired some woodpecker damage of about 1.5" deep by about 4" long. My mast flexes but I have not found any loss if integrity of the wood in the area of the repair - or anywhere else for that matter
Just some thoughts

 

[keelbolts]

3M makes a fairing compound that sets for sanding in about 20 minutes. For many years I used West with 410 fairing beads, but it's a fair amount more involved. The 3M stuff is basically a thin Bondo. I've read warnings that it won't stay on wood, but I've been using it for about 3 years now and I'm still happy. I can go around the boat applying the stuff &, by the time I get to where I started, I can start sanding. I can do in a day what it used to take weeks to do.