The optimum (in my opinion) is to:-
1) make sure that the ferro
side decks are properly sealed. There should be very thin epoxies sold for this purpose (soaks into the microcracks in the cement). It may be possible to use nice warm ordinary thin epoxy
, but there would be a very short window of opportunity and I have no experience of this.
2) Seal the wood to be bolted to the ferro
totally with good sealers. My choice would be thinned generic epoxy
followed by two coats of straight resin but other may have better options.
3) Set the wood up over the ferro with the bolts in place, but not tightened. I seem to recall
using 3/8" galvanised cup heads but on Boracay the same bolts have shrunk to 8mm. Extra long bolts and threads may help (They can be cut off later with a cut off blade on an angle grinder, hopefully before they take skin off various parts
of a body).
4) I prefer to use huge quantities of mastic, but I'm a bit of a mud lark from way back. Neat and tidy is nice if you can do it, but I'd go on the extra side if there is any doubt. Additional workers to help are good at this stage. I used to use silicon but there is so much discrimination these days that I have been forced to use polyurethane
. I don't go with top of the line super dooper marine
grade, if you know what I mean. Better a join filled with lesser mastic than voids with the expensive stuff. Lots of turps and rags or kitchen paper helps.
5) After the mastic is in drop the wood onto the deck
and make sure that all lines up. There needs to be enough mastic to tighten up against it after it has set.
I don't know what your setup is like but hopefully my comments can suggest what worked for me.