Anyone know how to install deck hardware that doesn't leak?

[sailorman]

I think I will get some Arkobol 1000 or something similar. Are all polysulphide sealants pretty much the same?

Also, where is a a good place to get them - obviously not our local chandlery!

I think I will try the countersink trick - is there a certain depth that is best? I am consious that very mm I drill out will be weakening the deck!

Do you nip it right down to leave a 1mm raft or do you just tighten it right down?

Cheers

Carl

builders merchant
B&Q

 

[Davegriff]

Try google. A couple of years ago I found a blog (American I think) where this bloke set out in great detail the process of using butyl - hole sizes, countersinking etc. Really informative and detailed. I usually download pages like that, but dont seem to be able to find it right now. If I can find the site again, I'll post a link.

An important point, I think, is not sealing the inside of any holes made. You don't afterall want any water that does happen penetrate, being retained inside a laminated deck, but allowed to drain away.

 

[Davegriff]

Well, I think someone has already posted some of these pics, but here's a detailed guide to using butyl.

http://www.pbase.com/mainecruising/rebedding_hardware&page=1

 

[lw395]

I think I will get some Arkobol 1000 or something similar. Are all polysulphide sealants pretty much the same?

Also, where is a a good place to get them - obviously not our local chandlery!

I think I will try the countersink trick - is there a certain depth that is best? I am consious that very mm I drill out will be weakening the deck!

Do you nip it right down to leave a 1mm raft or do you just tighten it right down?

Cheers

Carl

I've no firm opinion about the relative merits of different brands of sealant.
In some ways I'd trust a freshly opened tube of cheap stuff above a tube of Sika that's been open too long.
If I decide something needs to end up with a 1mm bed of rubbery stuff under it, I achieve that by cutting a rubber/neoprene gasket and firmly tightening down with sealant. If you make the bolt holes big and fill them with goo, it works similar to countersinking.
The countersinking does not have to be deep, a 1mm bead of sealant should work in all the circumstances I can think of. When it's self tappers being used, I countersink a bit deeper, to account for distortion of the deck material by the thread.
I think priming of porous materials is important, particularly silicone on wood. Polyurethane sealant is less fussy.
People mock silicone as being only any good for bathrooms, but I find it works. I use it on fittings on GRP dinghies where I do an air pressure test where fittings are bolted into buoyancy chambers. It works for me, although I'd use polyurethane or polysulphide underwater on a yacht.

 

[sailorman]

I've no firm opinion about the relative merits of different brands of sealant.
In some ways I'd trust a freshly opened tube of cheap stuff above a tube of Sika that's been open too long.
If I decide something needs to end up with a 1mm bed of rubbery stuff under it, I achieve that by cutting a rubber/neoprene gasket and firmly tightening down with sealant. If you make the bolt holes big and fill them with goo, it works similar to countersinking.
The countersinking does not have to be deep, a 1mm bead of sealant should work in all the circumstances I can think of. When it's self tappers being used, I countersink a bit deeper, to account for distortion of the deck material by the thread.
I think priming of porous materials is important, particularly silicone on wood. Polyurethane sealant is less fussy.
People mock silicone as being only any good for bathrooms, but I find it works. I use it on fittings on GRP dinghies where I do an air pressure test where fittings are bolted into buoyancy chambers. It works for me, although I'd use polyurethane or polysulphide underwater on a yacht.

If ever you need to paint a deck silicone should be avoided as nothing sticks to it. Our yard sprayers cringe @ if the word silicone is uttered

 

[Ian_Edwards]

Butyl tape for skin fittings?

Anyone successfully used butyl tape to seal skin fittings?

I was thinking of using Sikaflex 291, as per an earlier post of mine, until I saw this thread, but having taken 2hrs, of hacking with a scalpel and a craft knife, to get on old fitting off, I was wondering if butyl tape would be as a reliable as Sikaflex for prolonged immersion, but easier to remove.

 

[sailorman]

The problem with tape is that due to its thickness it keeps being squeezed out by the applied pressure of the fixings, thereby getting just slightly looser over time. I prefer a mastic that is more likely to leave a thin membrane.

 

[lw395]

If ever you need to paint a deck silicone should be avoided as nothing sticks to it. Our yard sprayers cringe @ if the word silicone is uttered

Good point.

I think the silicone you most want to avoid is in cheap polish.
Paint won't stick to silicone rtv sealant, but I don't find it contaminates the rest of the deck.
I tend to mask around where I am using sealant.
If you have peeled silicone rtv off an area you wish to paint then thorough cleaning is probably called for.
Gloss paint goes into 'fisheyes' in the presence of silicone wax traces. I don't think deck paint tends to do this?

 

[sailorman]

Good point.

I think the silicone you most want to avoid is in cheap polish.
Paint won't stick to silicone rtv sealant, but I don't find it contaminates the rest of the deck.
I tend to mask around where I am using sealant.
If you have peeled silicone rtv off an area you wish to paint then thorough cleaning is probably called for.
Gloss paint goes into 'fisheyes' in the presence of silicone wax traces. I don't think deck paint tends to do this?

I am talking coach roof resprays not the decks as such

 

[Lakesailor]

See reply no.6 for why sikaflex isn't always the best option.

I don't like silicon sealants and haven't found them as effective as Sikaflex. They 'peel' off some surfaces, but Sikaflex seems to stick to anything! I note that cheaper polysulphides are available.

I was thinking of using Sikaflex 291, as per an earlier post of mine, until I saw this thread, but having taken 2hrs, of hacking with a scalpel and a craft knife, to get on old fitting off, I was wondering if butyl tape would be as a reliable as Sikaflex for prolonged immersion, but easier to remove.

I've used other sealant/adhesives but find Sikaflex 291 reliable and have not had any problems removing fittings. Had some of those problems been with 292 perhaps?
The smaller tubes available now make it less prone to wastage.

Advantages & Benefits of Sikaflex 291i 300ml Marine Sealant:

Use above and Below the Water Line
Resists Salt Water
Fast Strength Build up
Stable
Paintable
Sandable
Excellent Bond Strength
May be squeezed or brushed into place