TruDesign seacocks

Posted by Big-Introduction-941@reddit | sailing | View on Reddit | 23 comments

So i've bought trudesign fittings for my whole boat, which i am in the process of fitting next weekend. And i have two questions for the installation.

When i've replaced through hulls earlier, i've only done ones in brass. And when i have installed those, i've simply just put lots of sikaflex snd screwed the nut down as hard as i can. Reading the instructions for trudesign, you recommend hand tightening, and then waiting 24 hours and do half a turn ( to sorts create an o-ring effect of the sikaflex)

isn't there a risk of the sikaflex adhesion getting released from the hull when doing this?

Is it possible to do it the trafitional way? And if so, should i skip the washer and just use the nut?

And second question: for the ball valve, is it recommended to use sikaflex here aswell on the threads, To create a permanent fit? How hard should the ball valve be tightened if doing so? Or is it better to use something like loctite 5331?

With the brass ones i've used earlier, i have applied ptfe tape, and it got tighter and tighter, but when i've dry-fittes the trudesign ones it goes easy all the way until it suddenly stops. Is this where i should stop screwing it, or should i apply more force and tighten it even more?

[-]

windoneforme@reddit

I went with the epoxy them in place route. My boat had flush thru hulls originally, however the profile of the flush thru hill fittings that was there and the Trudesign ones was different.

My solution was to grind out the profile to roughen up the area, and sand the skin fittings. Then I filled the indents partly with total boat self mixing epoxy in a tube. After it had time to gel but not fully set I put in the skin fitting with more epoxy and tightened. I then inserted a rolled up piece of paper in the skin fittings, and applied more epoxy on top to make it flush with the hull. The next day I came in and sanded down everything flush and used a bit of sandpaper in the hole to remove the paper. It's been a few years and no issues.

I used the load spreading fittings over the skin fitting stem under the vales and opted for whatever sealing on the thread they recommended wasn't permanent so I could in theory some day remove just the vales in case I needed.

Keep in mind the skin fittings are straight thread and when you are screwing them in until it stops it's simply bottoming out at the end of the threads, these are not tapered pipe thread.

When you dry fit them you should trim the skin fitting to the right length for your hull thickness, washer, nut, and the right amount of thread engagement with the valve. Also make sure after you trim and dry fit it again that your handles will rotate and are facing in the desired direction when it's tight, then mark the skin fitting head and hull with a sharpie to keep that orientation.

I definitely got some odd looks from the yard staff during the process, but they'd either not used the Trudesign yet, or hadn't installed them with epoxy.

Overall I'm very pleased with the product my installation is permanent and if all goes well I shouldn't have to worry about replacing them again. Remember to exercise the valves once a month or so when in the water. Overall their instructions were very thorough and I'd follow them to a T, they know what they're doing.

bill9896@reddit

If somebody doesn't know the difference betwwen brass and bronze, I wouldn't want them working on my boat's thruhulls! And pipe tape on straight threads???? Geezzz...

Big-Introduction-941@reddit (OP)

1.) I know the difference between brass and bronze. 2.) Teflon tape is one of the recommended ways trudesign states.

So what's your problem?

If you know the difference between brass and bronze why would you ever install brass seacocks? You have heard of dezincification??? And real bronze seacocks have parallel threads. tefon tape does not properly seal parallel threads. You should use a paste type sealant. Polyurethane is usually recommended, but other curing type sealants work.

Because that's what they sell at all boat shops around here? Dezinficied brass, not bronze. Why do you think i'm going with TruDesign?

Well apparently it does seal, since my last boat was still floating with no leaks after 10 years with them. And the current boat i have now, where i'm replacing the brass ones, have held for 48 years.

What i'm asking is about the trudesign ones, and how people who have actually installed them have done.

wheezl@reddit

> "And when i have installed those, i've simply just put lots of sikaflex snd screwed the nut down as hard as i can."

This was never correct. The way TruDesign recommends is actually the recommended approach for the other through-hulls as well.

I have installed the TruDesign on my boat and other than the 5200 recommendation (which I begrudgingly followed) the install was really straight forward. If I ever have to replace them they should come out pretty easily with a hole saw so 5200 isn't the end of the world. IIRC 5200 was recommended for the seacocks as well but you could easily just ask them if it isn't clear.

You mentioned them suddenly stopping. Have you cut them to the proper length? They might be bottoming out before getting tight enough.

Congratulations on replacing the eurotrash brass through-hulls. I have no idea why they use that crap over there.

millijuna@reddit

We followed their instructions when upgrading our engine seacock as part of our repower.

We made a flat washer of G-10 fiberglass and bedded that against the inside of the hull so that the compression ring on the through-hull had something to press against evenly. We then bedded the whole thing with sikaflex and followed their instructions to set the whole thing after a partial cure.

The thing you have to remember is that the threading on TruDesign kit is not NPT. Tt isn’t conical, so it’s not something that gets tighter and tighter as you go out. The threaded sections are cylindrical.

What we were told to do is to dope up the threads, run them in until they bottom out, then back off a quarter to half a turn. Because we have no intention of ever taking this apart again, we doped up the threads with Sikaflex as well. If we ever have to take the seacock/through-hull off again, we’ll saw it off.

But absolutely do not apply more force. When it stops turning, you’ve bottomed out the thread. Run it all the way in, then back off to the angle you want. Use a liquid pipe dope.

alex1033@reddit

I use Loctite 55 for all threads. It's revolutionary better than anything else I used previously.

deltamoney@reddit

True design is good. I have them.

I also have done Forespar Marlon valves.

Both are good. The true design needs a lot of height clearance. Marlon has stubby valves available. Both are high quality.

I recommend creating a new backing plate out of g10 1/2in. You can epoxy that plate in to create a flat mounting plate surface and you'll be good to go forever.

Aplay1@reddit

3M 5200 seems to be the good to for seacocks, but follow the manufacturers directions and you can’t go to wrong

PDQ-Cobalt-252@reddit

Never use 5200 for fittings. Use 4200. 5200 is permanent and used for things like a hull topsides deck joint. A fitting by its very nature has a lifespan that requires replacement.

It’s advertised specifically for though hull fittings.

It's fine under the water line. So is 4200. They cure with moisture.

d3adfr3d@reddit

5200 is absolutely safe under the waterline. It will actually cure faster in the water.

This is just internet lore. I remove valves and other harware installed with 5200 regularly at work.

Can it be difficult? Sure. But with the proper application of heat and torque, nothing is permanent.

In my opinion, you want the adhesive quality of 5200 on threaded connections below the water line. This is doubly so for BSPP and NPS threads like these plastic valves.

You need low to mid adhesive quality. Not extreme adhesive quality.

IDK if I'd call it internet lore. One is an extreme adhesive meant to be permanent, the other is adhesive/ sealant meant to be semi-permanent.

Free_Range_Lobster@reddit

5200 is absolutely fine for thru hulls. And no, its not permanent, y'all are just terrible at removing things.

My personal opinion is that 5200 for anything other than extreme structural uses where an adhesive is needed like keel joints. It's not the right product.

Seacocks don't need extreme mechanical adhesives. Thats what the threaded nuts are for. They need mild adhesive with sealing.

I personally use 5200 as a last resort now. I've seen it rip fiberglass out. For 99% of repairs or uses... That's too much. 4200 is a better choice for most of these things.

jugbrain@reddit

I prefer 3M 4200, because eventually everything we put on a boat will need to be replaced. Removing something bedded in 5200 will more likely cause damage the surrounding GRP when the next owner needs to replace the seacock.

RedditIsRectalCancer@reddit

Sweet, let me make some popcorn for this holy war.

salty-shanty@reddit

I fitted true design about 5 years ago and followed their 24hr instruction. All has been good …S

Nibron@reddit

Just replaced all of mine - followed the trudesign instructions. If you use the washer, the half turn after curing means the nut is compressing the sika and not tearing it.

Used sika 291i (like they recommend)

Also used the same on the valve thread - I don't see any scenario where I'd want to remove the valve anyway

Foolserrand376@reddit

I have not used Tru Design, but I've used the Marelon full flow. Every haul out over the last 5-6 years I've replaced 2-3 of the 35 year old bronze thruhulls/seacocks. from a time/manpower POV i sealed up with 4200 and tightened everything up in one pass.

the skin fitting would bottom out on the seacock regardless. to get a snug fit on the hull, i had to trim the skin fitting to account for the thickness of the hull and backing plate. The possible reason for the bronze to get tighter, while the TD bottoms out could be the type of thread. tapered Vs straight. if the TD has straight threads.

I used teflon tape on all the threads. The Marelon is a bit different in that the skin fitting and valve are one piece while the TD has a skin fitting separate from the valve.

Do take the time to index the valve such that when you tighten it down, its in a spot that you can easily operate it.

Are you adding the load bearing collars?

Also make sure that if you let it sit for 24h before the final tighten. Make sure that you have a helper outside or some way to ensure that the skin fitting does not rotate when you tighten. If the skin fitting rotates, you will have to remove and start over.