When it comes to puttying up


New member
25 Oct 2001
As some of you will be aware I am resoring Mystico over in Cyprus, you have all given me good advise on decisions which would have otherwise given me sleepless nights. Here's the next one, When it comes to puttying up do you use Sikaflex, two pot epoxy filler or white lead putty, the problem with the last being the difficulty in getting it out here, your imput on this one will be much appreciated.




Active member
30 Nov 2002
A vote for white lead putty

I suppose that ordinary linseed oil putty is available in Cyprus, so it is just a question of adding 1/5 of white lead putty to it and beating it in (red lead below w/l, of course!).

Classic Marine (http://www.classicmarine.com) carry the white lead already ground in linseed oil, along with most everything else, and will ship it against a credit card over the phone.

I am assuming you are speaking of filling seams after recaulking or hardening the caulking.

For final stopping up of the topsides, on top of the priming coat(s) or sandwiched between the priming coats (better) all the paint makers do a "traditional" knifing stopper/trowel cement which comes in a tube these days and since Mystico is about the same size as Mirelle you will need 5 or 6 tubes I reckon! This stuff should be easily available in Cyprus from any yacht chandler who sells one pot alkyd (traditional one part) paints.

The two part epoxy fillers are very good but a bit awkward to use in small quantities; fine for below the w/l though, where you can't use knifing stopper. No good in seams, because they set hard.


Epoxy fillers and glues

And a very good they are to but a only in the right places, the problem with them is that they are harder and stable so stable in fact that they expansion and contraction is miniscule. On the other hand the expansion and contraction of wood is not only large but in reverse to the epoxy.
The epoxy will expand very slightly as it warms up and contract again when it is cooled (something like 0.001% a)
Wood contracts when it drives out in the heat and expanse again when it cools down with emersion in water. (something like a 1 or 2%)
Now however well the epoxy adheres to the wood the stresses involved will eventually break the bond. Certainly a lot quicker than traditional fillers and glues which generally have similar expansion and contraction to Wood.

The reason why you can get away with using epoxy on cold moulded hulls and top-marsts is that the Wood content that is not impregnated with the epoxy is extremely low if anything at all. The epoxy and effectively holds the wood fibres together in effect making WRP (Wood Reinforced Plastic) the ideal wood to epoxy ratio is 30% epoxy 70% Wood. The problem with all fibre reinforced composites (that is what cold moulding is) is the the adherence of the fibres to the Matrix.
Which brings us back to the use of the epoxy fillers and glues on a traditional wooden hulls. Now there's an interesting subject.