Bow roller sealant

[alexincornwall]

Hi all,

We'll shortly be relaunching following a long winter of maintenance including having our topsides repainted. The contractor that carried out our the paintwork is in the process of demasking and completing any final odd jobs, to include reapplying silicone around the forestay chain plate (marked green in this old photo, the best I have to hand). He indicated that there was no silicone present where the bow roller meets the hull/bulwarks (circled red). From memory, I think he is right as I recall thinking it odd. Is there any reason why the vertical and horizontal gaps wouldn’t have been sealed?

I’m inclined to ask him to go ahead and get a decent bead of mastic in there. I also think it would make good sense to apply a thin bead running the length of the boat where the toe rail meets the bulwark on the outside edge. I'm not a huge fan of silicone but given the nature of the job, this seems an appropriate product as no adhesion is required and it obviously needs to dry.

Does anyone have any thoughts on this please? I'm now wondering if the bow was deliberately fitted unsealed to allow and water ingress to run off/dry out.

Many thanks

 

[Poignard]

Does anyone have any thoughts on this please? I'm now wondering if the bow was deliberately fitted unsealed to allow and water ingress to run off/dry out. View attachment 190690

Many thanks

Provided the screws securing the bow roller bracket are sealed so that water cannot pass along them into the hull I can't think of any reason why the edges of the bracket need sealing.

 

[Rappey]

Is there any reason why the vertical and horizontal gaps wouldn’t have been sealed?

Lines of sealant on disimilar surfaces rarely last long. The sea water gets behind it and can cause corrosion. Left open the water can escape ?

 

[Neeves]

Are you sure that silicone is the best product? or are you using the word 'silicone' loosely to mean mastic, like Sikaflax.

 

[oldbloke]

Unless there is evidence of water getting into the boat I can't see what you are trying to achieve

 

[Daydream believer]

Silicone as a sealant is of no use on a boat.

 

[Boathook]

Silicone as a sealant is of no use on a boat.

I had some silicone sealant a few years back and it did a very good job. It was expensive unlike the normal silicone sealant you can buy.

I find this good on the boat https://www.screwfix.com/p/fernox-ls-x-leak-sealer-50ml/23614 Expensive, but for small jobs works well.

 

[vyv_cox]

Smearing sealant on the outside of a joint is close to a waste of time and money. The correct thing to do on the chainplate is to remove it or slacken it off, then rebed it on a good sealant. This should prevent any ingress of water and prevent unsightly rust stains due to crevice corrosion.

 

[dgadee]

Revisiting this thread.

I want to bed a bow fitting but it rocks slightly from side to side. I don't want to grind away the deck to make it flat. What should I use as a mastic which will set solid?

 

[KevinV]

Revisiting this thread.

I want to bed a bow fitting but it rocks slightly from side to side. I don't want to grind away the deck to make it flat. What should I use as a mastic which will set solid?

I don't like the sound of that at all, a joint being pulled will never stay sealed.
I'd be inclined to make a bed of thickened epoxy (with suitable release on the metal), so the fitting is solid without putting undue pressure on the fixings. Then bed onto that with your sealant of choice.

 

[Poignard]

https://www.westsystem.com/app/uploads/2022/10/Fiberglass-Manual-2015.pdf

Page 50, section 7.3.

 

[dgadee]

I know, I know. Epoxy is what I thought of using, but then wondered whether there might be something else.

Epoxy mix it is.

When I installed my hydrovane I put the epoxy mix into a plastic bag and put it between hydrovane pad and the hull. Took it out of the bag, cleaned up the edges and it was a great fit. Worked brilliantly.

 

[KevinV]

I know, I know. Epoxy is what I thought of using, but then wondered whether there might be something else.

Epoxy mix it is.

When I installed my hydrovane I put the epoxy mix into a plastic bag and put it between hydrovane pad and the hull. Took it out of the bag, cleaned up the edges and it was a great fit. Worked brilliantly.

Clever, I am going to shamelessly nick that idea