Floor through hull fixing bolts

[mulligan]

Could anyone help with the above, I am currently in Cyprus working aboard Mystico and working on replacing the floor fixings. she originaly had bronze which were in as good a condition as the day they were put in in 1937, could anyone suggest a more cost effective replacement, she has wrought Iron floors if that helps.

Kind regards

Ross Davis

 

[Guest]

Sorry but

If she has bronze fixings which art as good as the day that they were fitted why are you changing them?
For the only alternative which is better than bronze would be moral! But it is a touch pricey!! whatever you do not fit stainless-steel.

-{)>

 

[mulligan]

Re: Sorry but

The reason I am taking the bronze fastenings out is to replace the floors with galvernised iron items, any more suggestions would be much appreciated.

Regards

Ross

 

[ccscott49]

Re: Sorry but

Dont fit galvanised floors, even with bronze bolts you will get rot around the bolts in the timber, I suggest you stick with iron, suitably blasted and then dipped hot, into hot tar, or treated with cold tar epoxy on an etching primer, then refit bronze bolts. Monel is horrendously expensive! The bronze is a lot cheaper than you think. My brother ahd problems with his converted lifeboat with galvanised floors and bronze bolts, as the lifeboats were never built to be left afloat as they are today, well some anyway. They galavnised floors set up a
n eletrolitic corrosion, which damaged the teak around the bolts. The way he got around this, was to remove the galvanisation, cold tar epoxy and insulate with an epoxy plug from the surrounding timber, I suggest all you need to do is shot blast the floors or remake them and treat as above, then refit ther bronze bolts. Ensure the iron is spotless and rust free before coating, they shopuld then last 30 years! at least! Bronze bolts and threaded rod is available from anglia stainless steel, in suffolk, if you want there address, I'll try and find it!

 

[Guest]

bronze floors ???

I couldn't agree more galvanise floors and bronze Bolts do not sit well as bed fellows. keep dissimilar metals apart if only separated by a coat of epoxy you could try fitting top-hat washers made out of plastic or a like
it may be worth your while considering using the old floors as patterns for new "bronze" floors or getting some bronze floors fabricated up out of sheet bronze.

-{)>

 

[Mirelle]

Cost of bronze

Is the keel lead? If it is, then bronze floors, cast from the wrought iron ones as patterns (but with good deep fillets, and generally beefed up, as bronze is weaker ) are I believe the recommended solution. One friend had his Albert Strange "done" this way and another had his Harrison Butler likewise "done" and they are both delighted with a permanent solution to the problem.

Having an iron keel I have just renewed quite a few floors in wrought iron, and I used galvanised bolts for them. Not ideal, espescially as they pass through oak frames, but I know now that they need to be "done" every 10-15 years, and if the boat has done 65 years this way they cannot be too bad.

On the other hand I used bronze bolts to resecure the chain plates, etc, above the water line, and these are about the same size and came out at about a tenner each. Not too bad.

 

[ccscott49]

Re: Cost of bronze

I think the chap was asking for a cost effective way, re-casting in bronze with fillets etc, in cyprus is not going to be cheap, if he can get to turkey however he may be surprised how cheap bronze casting is there! I agree, bronze floors is the way to go, but as we've all said, wrought iron will last a long time and is cheap strong and easily available in cyprus. With the cold tar etc, they should last a lifetime, mine anyway!

 

[Guest]

There may be a easier method of course.

I'm not sure if anybody has tried this but why not? cast up a the floors in a reinforced composite such as glass /a carbon-fibre/epoxy Matrix?
This could always be done in place to get a perfect fit!
Before you traditionalist through your hands up in horror how many of you have a carbon-fibre top mast ?

-{)>

 

[ccscott49]

Re: There may be a easier method of course.

He could of course use the ultimate method, laminate new floors from timber, use galvanished bolts, knocked in through cold tar epoxy, he would never have anymore problems, no disimilar metals, no galvanic corrosion! But we were talking cost effective. It also depends on what his hull is fastened with aswell, copper etc. I realise there are many ways to skin a cat, but carbon fibre, glass and epoxy! I dont have a carbon top mast, don't have a top mast but whats the matter with cold moulded WOODEN hollow top masts?

 

[Guest]

Cost efficiency

The disadvantage with steel/iron/ bronze is unless you have access to a metal-bashing shop they are very difficult to home produced, where the composites are relatively easy to manufacture with a little care and a great deal of cleanliness.
As for carbon-fibre top-marsts I understood from earlier posts are here or elsewhere that an X windsurf mast was preferred solution to replacing with a wooden Spar! Especially when weight and cost is considered
Merry Christmas whatever your spas are made of. (is it me or is a there nothing on the telly box tonight)

-{)>

 

[mulligan]

Re: There may be a easier method of course.

I had thought of laminating some floors in the wineglass area below the engine, but I must admitt I had not thought of putting wooden floors in other areas. What problems could I expect from doing it in this way and would it be strong enough for this application.

Happy Christmas

Regards

Ross

 

[ccscott49]

Re: There may be a easier method of course.

Laminated or grown floors will be plenty strong enough, the reason iron floors were put in your boat, was, sorry, cheapness and smaller dimensions, but cheapness really, you will of course need larger than iron, but wood especially laminated, is a fabulously strong material, if you have room for them, fit them! Remember you will need new bolts, but could then use galvanised. Keeep the bolts dry and you will never have a problem with them, the same goes for the iron/bronze bolt situation, keep them dry, drive them in with cold tar epoxy and you wont have a problem, i would be tempted to use the cheapest simplist way, that is remake the floors if too badly corroded and treat as I said, bed them in white lead or similar and drive the bolts in with cold tar epoxy, I dont think you will need to worry about them for many years. The main thing is keep them dry! No salt water, no electrolyte, no corrosion! The actual water content of the wood will eventually corrode them, but if you dry out each year, that will be put back decades!

 

[Mirelle]

I agree

I am quite happy to stick with iron floors and bolts; as you say, they will certainly see me out, and whilst there is a fair chance that the boat will outlast me, she will only do so if I spread my few available pennies as far as they will go; one so often sees restoration attempts that have petered out halfway because the owner attempted to have everything of the highest possible spec!