Thru-Hull Sealant / 4200 or 5200

[Maine Sail]

Rob..

To answer your original question here's my preferred order of sealants for through hulls.#1 3M 101 (Hamilton was out of stock on my most recent job so used Sika 292)#2 Sikaflex 292 (fast drying can launch in 24 hours similar adhesion to 4200)#3 4200 (Slightly more tenacious than 292 but far less than 5200)Any of the above would be fine but the order is my personal preferred order after years & years of DIY and hanging out at places such as the Hinckley Yard and soaking it all in....As far as people not caring about their own personal safety or caring to know where the pump out is etc. I have taken it upon my self to try and help those with less mechanical aptitude with my photo based articles like this one: http://www.pbase.com/mainecruising/stuffing_boxor this one: http://www.pbase.com/mainecruising/catalina_36_alternatorI really wish more of us with the skill and experience would tote the digital camera along more often, and create more how to articles, for those less informed. The more boats that are maintained well, with the help of this board and others, means I don't have to look at 50 boats, like I did this winter, to find one good one!!

 

[Bill Roosa]

Should I use xxx or yyy

Stating the problem in term of the answer is not a valid way to get an answer. By stating "I have a problem sealing a thru-hull" and then asking "should I use xxx or yyy" really implies that you know the answer is either xxx or yyy and you want an opinion on either one. Well since you don't know how to fix the problem perhaps you also don't know the best product to fix it.There seems to be a fixation on adheavises. Not sure why that is as you are clearly looking for a sealiant not an adheavise. An adheasive will not flex and will be hard to remove if (when really) you have to replace the fitting. A sealiant will fill the voids between the curved hull and the flat thru-hull fitting base.

 

[Tom S]

Bill it might be too easy to try & categorize

Many of these products could be categorized as both Adhesives and Sealants.Take 5200/4200 for instance, its is very flexible. I know it would be a huge mistake for one to use it as caulking for chainplate deck openings, but I know people that use it and have had very good results. (I have no idea how they plan on recaulking whenever it eventually does start to leak, even if its a long time. I guess they'll use DeBond 2000 to soften it and then scrape it out)While 4200/5200 is a very tenacious adhesive its also a very good sealant and is very flexible, thus the good results for thru deck for chainplates. I use 4200 when mounting wood blocks on the hull to drill things into and I have noted there is still quite a bit of flexibility in the caulk and fills gaps well.Then you have other products that are part Polyurethane and part Silicone *o Like "Life Seal" which I happen to think is one of the best products for caulking when rebedding opening hatches in your deck. Far superior than Regular Marine Silcone which I feel doesn't have the adhesive properties needed for this type of job. Life Seal has extreem flexibility of Silicone and adhesion of a Polyurethane I think the question comes down to "how much" adhesion do you need and "what" two materials you are adhering together.As noted earlier though, mostly everything that was posted in this thread has been written about ad naseum and would be found in a brief search of the archivesNow that we've beaten this horse to death I wonder what Rob used for his through hull ?

 

[Peggie Hall HeadMistress]

Oh hell, Ross...

At least half the people who post replies don't even bother to read any of the previous replies! At least half of them don't seem to have read any previous posts about the same topic, and at least half the remainder just repeats what someone else has already said.I'm beginning to think I've finally gotten too old to keep doing this...

 

[Rob19574]

The Job

OK all -I used 4200 because that's what my shop had. I can tell you though - this has been some learning experience for me and I am sure many others. I really appreciate the feedback, opinions and reccos.Against the recco of the board - I went with a bronze thru-hull and ball valve (all bronze) - not because I was trying to cut corners but because the space I was working in was extremely tight and would barely allow for a backing plate (not to mention the larger base seacock). That was the source of the problem in the first place...the nut on the thru-hull was leaking as it had no plate to snug up against!! I am up against the muffler and engine bulkhead and the hole was installed just an inch off to the wrong direction if you know what I mean. All the other thru-hulls have a plate and are in great shape. I managed to fabricate a small backing plate out of marine grade plywood and then painted it. I installed that with 5200 and let it set. Then I put the thru-hull in with 4200 snugged up the nut - all looked good. I then installed a new bronze ball valve with pipe compound joint and the hoses to follow.If I ever have problems with it again I think I am going to close up the hole altogether and just T into the seacock the head uses (my head sink drain and head intake line)....I really don't understand why Catalina went below the waterline Thru-hull happy. I have 5 and could probally get it down to 3.The yard I am using is in a rather remote location from the nearest marine supply shop so you know how a simple job could take days with trips back and forth for supplies.I installed everything today and she is being launched tomorrow. I am really looking forward to getting out for a sail with the wife and kids! My knuckles took a beating today in the bilge!Thanks again everyone for the advice!PS - boat is a Catalina 30 / '78.Rob

 

[Ross]

Awwww Peggie, I can feel your pain. I tell my wife

about some of the posts that we see here and she wonders why I keep coming back. I am beginning to share her feelings. Does anyone buy books and then read them any more? We have such an abundance of information available on the internet and so many people expect someone else to google the key words and hand them the answers on a silver platter.

 

[Maine Sail]

Rob teeing

Teeing into the head through hull is a bad idea unless you valve it off or install very good quality check valves that will hold up to salt water. I currently know of no good quality check valves that last for more than a couple of years before gumming up. The reason it's bad is that air is easy to suck and your impeller will back suck air from the head thus sucking a lot of air and some water and eventually burning out your impeller or overheating your engine.Just patch the hole and move the engine water intake. On some fancy expensive yachts they sometimes use a below the water line "water box". The box has one large through hull then all the intakes suck from the box each with their own valve. This gives you only one through hull opening for many intakes and no way to back suck air. The problem is if that one big through hull goes bad now you have NO intakes....

 

[Peggie Hall HeadMistress]

Ross, I'm gonna be in Annapolis during the sail show in

October...The SSCA has invited me to speak at their GAM there this year. Let's get together and commiserate about all this over a tall cold one there? All others on both side of the issue invited too.And btw...I agree with Maine Sail...teeing the engine water intake into the thru-hull for any other device is a bad idea. It's one thing to fry the impeller in an electric toilet or a washdown pump, or evem heat/ac...quite another to risk frying your engine intake impeller.

 

[Napa Ed]

mechanical seal

I had to replace an underwater thru hull while the boat was in the slip. Used an O-Ring. Really fast cure time and the thru hull came off clean two years later during a haul out. Cheaper than a tube of anything.

 

[Ross]

Peggie, I have been looking for a good excuse

to return to the boat show. (it has been several years) We will plan it. I usually go on trade day(Thursday)the tickets are cheaper and traffic is not so bad.

 

[Larry Wilson]

re:5200 vs 4200

I have to jump in here.Every question that could possibly be asked about a sailboat has probably been discussed and/or answered on this forum at some point in it's history. So why not just close the discussion forum, and let the archives live as a monument to all of the anal jerks that have nothing better to do than post complaints about questions that have already been asked and answered? Because, everytime a question is asked, more, and different viewpoints are presented...and I for one, enjoy reading the new information presented. I think that perhaps the problem here, is not the frequency of the questions, but that the resulting e-mails jam up the mailboxes of those that subscribe to the email version of the forum. To those, I say, unsubscribe, and read the posts here on the web. No e-mail, no e-mail jam up. As to the original question....my oldest boat is 42 years old, and I am just now replacing the thru hulls. I doubt that they have ever been rebedded, and none of them leak at the seal. I have real doubt that the boat will last another 30 years, and so, could care less if the 5200 that I use today, might be nearly impossible to remove in 30 years. Larry WilsonRichmond,Va

 

[Ross]

Larry, I have no problem with seeing new questions

on well worn subjects. But I do have a bit of emotional response to the manner that some people ask questions. For example should I use abc or fgh for gluing my hatch shut. The answer is of course neither because you don't want to do that. As a response to your suggestion that we just convert the forum into a reference library that is of course as absurd as you intended it to be. However if we can steer a petitioner in the right direction by referring to an archive file AND if he will go there and read that file and all of the others on that subject and then go to any of several reference works that have been published and to the web site of the maker of the material that he has an interest in, then he will be better educated and will be able to answer questions from someone in the future.

 

[Peggie Hall HeadMistress]

Thurs won't work for me...I have to be in Solomons

Thursday and Friday...won't get to Annpolis till Saturday morning. Send me an email (I'm in all the directories here)...if we can find a mutually agreeable day and time, we'll bring it back here to see who else we can round up to join us.

 

[Larry Wilson]

re:re:5200 vs 4200

Ross,If this educated answer only directs the questioner to the archives, then why does he need educating in the first place? Most of the responses that do direct one to the archives simply say, go look in the archives. Unfortunately, many new boaters don't know enough about the language of boating, to know what to look for once they learn that there ARE archives. For the oldtimers, the archives are a valuable source of information, but for newcomers, it's like expecting a five year old to know how to use the Dewey Decimal System in a public library. I just entered "bedding thru hulls" in the archive search. There are 48 hits. Included are such topics as: Agreed!/ If you're determined to do this,/ 432,/Re:29.5 Ice in rear locker,/ Forward Cleats,/ Am replacing my.....,/ just went thru this,/ Odor in the head can be a dirty sump.....,/ Why Bother. There is very little continuity in the referencing to our threads, so that many replies are filed in who knows what subject heading. If you don't agree, enter the phrase "best wire for standing rigging" or " how to rebed a chainplate" .The resulting hits are varied and for the most part nearly unrelated to the question asked.