New through hull fittings.

wiggy

wiggy

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My launch has been so delayed this year it’s blending into next winter and as such I‘ve decided to replace all my through hull fittings whilst I wait for mast bits to be made, delivered and fitted, present through hulls are nearly 20 years old. I’ve decided to go for DZR for all the fitting but am unsure about sealant and joints.
1. What is best sealant for DZR to hull?
2. How do I get ball valves at the correct angle, space for handles is very limited and position is critical?
3. How do I seal ball valves to through hull and hose tails to ball valves?
4. Am I right in going for DZR over bronze?

Thanks in advance.
 
I would go for the new plastic skin fittings and ball valves. Trudesign? Made in New Zealand are very good and I believe that there are a few other makes as well. Proper bronze fittings (very expensive I believe) if they can be found are vastly superior to dzr imho.
 
I have just fitted trudesign. They look really excellent. With luck, I will come back here on Friday to confirm she floats...if not it'll be down to handiwork not materials.

The ball valves are larger than equivalent DZR but you can very easily take the handles off and reattach them after fitting.

1. There is an excellent user guide downloadable from Norris Marine that tells you how to fit. There are several options including epoxy (which I went for), and various forms of gunk.

2. Trudesign recommend min 20mm hull thickness. I suspect that's the same in principle for any skin fitting. I had to add some backing plates glassed in; in the process I could have changed the angle if required. A few strips of masking tape on the bulkhead helped indicate the angle of the original kit.

3. Again many options that are listed in the Trudesign manual. I have used Loctite 55 which is a sealing cord which I found very easy to use. The proof again will be in the launching ?

4. From my reasonably extensive but inexpert research, there is no problem with DZR. Do be careful that the whole thing is indeed DZR; the units I removed had a couple with failed innards that I think were brass.. No problem with bronze except the price (again, do be sure the innards are bronze too). The advantages of composite appeared to be: certainty that all components and innards WON'T corrode; the question of bond/not bond can be ignored.

The only thing I did wrong was using an angle grinder badly to remove the old ones. It's a perfectly good method (among a couple of others); I learned to my cost to apply the grinder at a perpendicular (making many passes) rather than acute angle (aiming to decapitate the mushroom). By the end I was really good at it...but on the first few removals I left myself with damage to gelcoat that I would rather (and could easily) have avoided.

Pm me if you want to chat.
 
Have you given any thought to whether you can design out any... I am thinking of copper coating next year and doing away with at least 7 below waterline through hulls...some consolidated some just routed to above waterline on the stern.
 
I fitted my first Forespar Marelon a couple of years ago and this Winter past have replaced all the rest with the same. No electrolysis to consider ever again, and as the boat is made from composite plastic, why not the seacocks and skin fittings too.

I will let you know if she sinks of course, assuming I survive !
 
I’m going to do this job this year. I will use bronze for its strength and corrosion resistance and buy in the US. I can’t find any here. Sealant used will probably be Sika and sealant of the fittings ptfe tape, though I have used pipe dope with success.
 
wiggy said:
My launch has been so delayed this year it’s blending into next winter and as such I‘ve decided to replace all my through hull fittings whilst I wait for mast bits to be made, delivered and fitted, present through hulls are nearly 20 years old. I’ve decided to go for DZR for all the fitting but am unsure about sealant and joints.
1. What is best sealant for DZR to hull?
2. How do I get ball valves at the correct angle, space for handles is very limited and position is critical?
3. How do I seal ball valves to through hull and hose tails to ball valves?
4. Am I right in going for DZR over bronze?

Thanks in advance.
Click to expand...
1. Almost any modern sealant except ordinary builder's silicone. Sikaflex 291i , Everbuild Puraflex40 (which is a similar polyurethane adhesive sealant), CT1 or Everbuild Stixall which is a silicone copolymer similar to CT1. ( Everbuild is a Sika group company. Stixall and PU40 are avaialble from Toolstation

2. By using "backnuts" to lock the valves in the positions you require. Or use a thread locking sealant such as Loctite 577

3. Use the same sealant as above or go upmarket a bit and use Loctite 577 which is a medium strength thread locking sealant suitable for parallel or tapered pipe threads.

4. Bronze is often used in place of DZR for the skin fittings themselves. I guess because it is stronger than brass. ( Avoid Tonval which in the past has been sold as DZR)

I expect some people wil suggest that you go all plastic with Trudesign or Forespar Marelon
 
Boathook said:
I would go for the new plastic skin fittings and ball valves. Trudesign? Made in New Zealand are very good and I believe that there are a few other makes as well. Proper bronze fittings (very expensive I believe) if they can be found are vastly superior to dzr imho.
Click to expand...
No room for plastic fitting unfortunately, space is very very tight.
 
pandos said:
Have you given any thought to whether you can design out any... I am thinking of copper coating next year and doing away with at least 7 below waterline through hulls...some consolidated some just routed to above waterline on the stern.
Click to expand...
I only have 4 through hulls, excluding the saildrive, log and depth.
 
VicS said:
1. Almost any modern sealant except ordinary builder's silicone. Sikaflex 291i , Everbuild Puraflex40 (which is a similar polyurethane adhesive sealant), CT1 or Everbuild Stixall which is a silicone copolymer similar to CT1. ( Everbuild is a Sika group company. Stixall and PU40 are avaialble from Toolstation

2. By using "backnuts" to lock the valves in the positions you require. Or use a thread locking sealant such as Loctite 577

3. Use the same sealant as above or go upmarket a bit and use Loctite 577 which is a medium strength thread locking sealant suitable for parallel or tapered pipe threads.

4. Bronze is often used in place of DZR for the skin fittings themselves. I guess because it is stronger than brass. ( Avoid Tonval which in the past has been sold as DZR)

I expect some people wil suggest that you go all plastic with Trudesign or Forespar Marelon
Click to expand...
Thanks for the great response, and not mentioning plastic fitting! I’d love to use Trudeaign or similar but just don’t have the space. Could I use the CT1 or similar on the threads to hold the ball-valve in the required position? Loctite 577 is hideously expensive.
 
Boathook said:
Through having purchased dzr fitting that went 'pink' after a few years whilst a 1970s fitting once cleaned up was perfect. Any skin fittings that I need to replace now will be done in composite plastic which includes the valve.
Click to expand...
My Blakes seacocks were installed in my boat when new in 1984. Blakes themselves do not know when their production changed from bronze to DZR but it was some time in the mid 1980s. I suspect, based on their colour, that mine are DZR. All three of them have minimal corrosion after 35 years.
 
superheat6k said:
I fitted my first Forespar Marelon a couple of years ago and this Winter past have replaced all the rest with the same. No electrolysis to consider ever again, and as the boat is made from composite plastic, why not the seacocks and skin fittings too.

I will let you know if she sinks of course, assuming I survive !
Click to expand...
Being US built, my boat came with them as standard. It's now 25 years old, with all the original seacocks. They just work.
 
wiggy said:
Thanks for the great response, and not mentioning plastic fitting! I’d love to use Trudeaign or similar but just don’t have the space. Could I use the CT1 or similar on the threads to hold the ball-valve in the required position? Loctite 577 is hideously expensive.
Click to expand...
Probably but to be sure they are locked firmly in the position you require use back-nuts ( lock nuts)

434307_3.jpg
 
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