Rub Rail Adventure

Jun 25, 2004
475
Hunter 306 Pasadena MD
Behind our (Hunter 306) aft cabin, I've seen something like 3 or 4 water trails coming down from the hull/deck joint when it rains, all of which either end up in the bilge, or under the teak panel which separates the aft cabin from the holding/fuel tank space. This has caused the teak plywood panel to delaminate and get nasty over 15 years or so. I'm mostly done with finishing the new panel, but it was time to address these leaks.

So I finally started pulling off the rub rail on the stern the other day. It's one of the very hefty white rubber rails with a narrow stainless steel strip screwed on the outer edge. Fortunately, the rub rail is in 3 sections, and the aft section starts a bit aft of mid-cockpit on one side (near where the arch is attached) and runs across the stern to the other side of the cockpit. So I only have to do the stern section, and not the whole thing. The stainless strip is attached with very shallow screws which are very easy to remove (except when the heads come off, which happened to 3 of them). I don't believe these even penetrate the rubber, so they're unlikely to be the source of leaks. I started by removing the stainless rail up to the joint in the rubber, and about 5 screws beyond, just letting the steel hang.

rub_rail1.jpeg rub_rail2.jpeg

Under the steel rail, they countersunk longer stainless screws (hidden by the steel rail) which were at least intended to screw into the 5200 in the joint between the deck and hull. These seem to be spaced at intervals of about 10-11 inches. I marked them with bits of blue tape (for reasons I won't try to explain) which you can see in the pictures. Once these were removed, the rubber rails came off on port and starboard sides with only moderate prying for the most part, but then I got really stuck trying to get off the 5 feet or so along the stern, under the boarding ladder. There were a few broken off screws there, so I thought that must be the problem:

rub_rail_broken1.jpeg

So a trip home to get some screw extractors.
 
Jun 25, 2004
475
Hunter 306 Pasadena MD
Surprisingly, I actually managed to extract 2 screws, but they were the little ones that secure the stainless rail. So they weren't the reason I couldn't get the rubber rail off. In the last picture above, you can see lots of holes that look like they are filled with caulk. These are only along the aft-most 5 feet of rail. Maybe they were hiding another screw or two? I eventually drilled into them all, removing little plugs of caulk: no screws. After about an hour of prying and swearing, I got to where I couldn't risk any more prying, so I just pulled really hard with both hands on the left and right parts of the rubber rail where it was already freed up. Much swearing later, I seemed to be making some progress. I could see an extra layer of "cushion" underneath, between the rubber rail and the hull/deck joint. More pulling and swearing and it eventually popped off:

rub_rail_caulk1.jpeg rub_rail_caulk2.jpeg

It turns out that Hunter had drilled a ton of small holes in the rubber rail just along the 2-3 feet to either side of the swim ladder, and pumped them full of caulk (presumably 5200). So the last bit of pain in getting this off was just fighting this adhesive. Just to be clear: what you're looking at above is a perfect mold of the inside of the rubber rubrail, made of 5200 and still wrapped around the hull/deck joint.
 
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Jun 25, 2004
475
Hunter 306 Pasadena MD
Anyway, in searching this forum, I hadn't found any really clear explanation of what was involved in pulling off and recaulking the rub rail, so I thought I'd share this. It seems like I just need to clean up the hull/deck joint, smear some caulk (I'm thinking 4200?) on the obvious cracks which were letting in rain, put more caulk into the groove on the rubber rail, and reassemble. I'm not sure about doing the same thing they did along the stern (i.e., injecting into all those small holes), but I probably will. I may even do a few new "injection points" in the problem areas which seem like they were leaking. For the most part, these seem to be the result of the workers messing up and missing the middle of the hull/deck joint when they put in the long screws to secure the rail. In fact, although they spaced these screws every 10-11 inches for the most part, there were 2 spots where they went nuts:

rub_4.jpeg rub_6.jpeg

At least one of these places cracked the fiberglass and caused a leak.
 
Oct 24, 2010
2,405
Hunter 30 Everett, WA
Interesting adventure. I think poor workmanship can likely be found on any boat. We've all seen it at one time or another. Congratulations on finding the leak.

Ken
 
Oct 29, 2005
2,355
Hunter Marine 326 303 Singapore
I got the yard to do similar repairs on my h326 rub rails about 2 years ago. Leaks on starboard side near arch (photos) and transom part near swim ladder (no pic) I didn't have to use any choice swear words ..... I'm sure the yard workmen did.

Ken Y
 

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Jun 25, 2004
475
Hunter 306 Pasadena MD
Interesting adventure. I think poor workmanship can likely be found on any boat. We've all seen it at one time or another. Congratulations on finding the leak.

Ken
Thanks, Ken. I mainly wanted to document how the rubrail was attached, for the next guy who needs to do this. This would have been a really easy repair if it hadn't been for the huge slug of 5200 they injected along the lowest part of the stern, which was completely unexpected. The rest of the rail came off quite easily.

The other thing I realized yesterday as I was cleaning up the joint and the rail is that 100% of the water-tightness is going to come from the 5200 in the actual joint (ok: that part is obvious) plus a small amount that they smeared on the joint to cover the thru-bolts and the joint itself. There seems to be maybe a 1/4"-1/2" gap between the hull/deck joint and the rubrail, which means there's not much point in running a bead of 4200 inside the whole rubrail when reinstalling it, unless I were to fill up the whole void with 20 or 30 tubes of 4200, which isn't happening. So the plan is to clean everything up well, smear more 4200 on the joint, giving extra attention to the 3 or 4 places where I can see cracks in the old 5200 in the joint. Let this cure, and then put on the entire rubrail, squirt a bit of 4200 into each of the holes for the longer screws (which go into the joint, or were supposed to), and put in all the long screws. I will probably inject a tube-or-so of 4200 into the lowest part under the swim ladder, as they did when they built the boat. And then finally, reattach the stainless strip with new screws.

Jay
 
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Jun 25, 2004
475
Hunter 306 Pasadena MD
I got the yard to do similar repairs on my h326 rub rails about 2 years ago. Leaks on starboard side near arch (photos) and transom part near swim ladder (no pic) I didn't have to use any choice swear words ..... I'm sure the yard workmen did.

Ken Y
In looking over the forum archives, almost all of the posts about leaks under the rubrail seem to end with either the dealer fixing it, or the poster saying it was fixed. Not much detail either way. Glad yours was dealt with!
 
Jul 1, 2017
64
Hunter 356 Brightlingsea
i had a similar problem with my H356. But rather than remove the rub rail completely, I removed the stainless strip, drilled 5mm holes through the rub rail to the depth of the hull join, roughly equi distant between the fixing screws. I then injected gap filling silicon (using a pneumatic gun as a manual one was just too hard on the hands) into the holes until it started to come out of the next hole, working my way all around the boat. That sorted my similar issues out.

Neil
IMG_5154.JPG
 
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Jun 25, 2004
475
Hunter 306 Pasadena MD
i had a similar problem with my H356. But rather than remove the rub rail completely, I removed the stainless strip, drilled 5mm holes through the rub rail to the depth of the hull join, roughly equi distant between the fixing screws. I then injected gap filling silicon (using a pneumatic gun as a manual one was just too hard on the hands) into the holes until it started to come out of the next hole, working my way all around the boat. That sorted my similar issues out.

Neil
Neil,

Interesting! So essentially, you replicated what Hunter did along the bottom of our boat, but going further left and right. (Except I'm 90% sure Hunter used 5200.) Thanks for the picture!

I caulked our deck/hull joint yesterday with 4200, after cleaning up the joint with a utility knife wherever there was an obvious crack. Tomorrow, the rubrail will go back on. I'll post more pictures as time allows. I plan to inject a bit into each of the holes for the long screws before installing them, and when I'm all done, probably inject a little into the many holes under the swim ladder as well, where Hunter injected the huge 5200 cushion.

Jay
 
Oct 29, 2005
2,355
Hunter Marine 326 303 Singapore
My yard Sup said he glassed over those leaks area. So I guess that'll solve it once and for all.

Ken Y
 
Jun 8, 2004
10,027
-na -NA Anywhere USA
@jaysweet
Send me a private message with phone and location. I might be able to advise. Former Hunter dealer now retired who introduced the 306

Crazy Dave Condon
 
Jun 8, 2004
10,027
-na -NA Anywhere USA
If correct, it would appear the boat was unprofessionally repaired. You should see pink material in the space between transom and the deck plate. There might be a Crack in the pink material.
It was designed the space between the deck and hull was filled with marine putty to the lip , sanded smooth with the back end of the boat with gel coat applied. That lip was above the waterline.

As on the 260, the rub rail was removed using a dremel to get out the old cracked marine putty cleaning to the lip top space of the deck pan and vice versa to the hull. Sanded smooth , I would clean using acetone. Then I would apply a two part epoxy using Water Tite. Depending on the depth, could take several times. That filler is a slow cure but was some of the best I used as it was very strong adhering to the upper and lower lip surfaces. Never had water penetrated thru. Sanded smooth. Instead of applying gel coat, I purchased a spray can from krylon using a white plastic paint. Putting back on the rub rail I would predrill using 5200 as a caulk on the screw threads as well as a bead around the hole. That will hold.

What I saw looked like an attempt to repair a leak before. I hope this helps. Send a private message if you want to.

Crazy Dave. Might even tell you how I got that nickname and who use to get home made moonshine that I helped make like Frank And Warren
 
Jun 25, 2004
475
Hunter 306 Pasadena MD
Thanks, folks, for your input! As of 1:30 this afternoon, the rubrail and stainless strip are back on, I very much hope for the remainder of my ownership. I basically did what I had proposed in my last couple of postings. Frankly, the reinstallation went quite smoothly, which surprised and pleased me to no end, as I was expecting 3 or 4 hours of extreme effort and unhappiness. Whether all leaks into the boat's after parts (so to speak) are eliminated remains to be seen. As threatened, I will post more pictures as time allows.
 
Jun 25, 2004
475
Hunter 306 Pasadena MD
So how was Hunter fastening the hull/deck joint as of 2004? Here are a couple of pictures of the (cleaned up) joint from the stern, directly below the swim ladder. This area had been protected by a huge slug of injected 5200, which I have trimmed away here. The joint in this area looks to be in really good shape: perfectly clean, and with no cracking. I'm mainly posting pictures to show that they alternated thru-bolts (with nuts on the other side) with essentially pointed wood screws. No complaints: it is what it is. Here's the top view, followed by the bottom view of the same 3 bolts/screws:
joint_top.jpeg joint_bot.jpeg

And here's after I gooped it up with 4200. I left the old adhesive intact if it looked good, but trimmed it away and applied new if not.

joint_after.jpeg
 
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Jun 25, 2004
475
Hunter 306 Pasadena MD
Here are a couple of shots of some bad places in the joint. Sorry that I only took them after I had trimmed away the 5200, which originally showed some serious cracks which were letting in rainwater. The first picture is of a maybe 1 foot long stretch on the starboard side where the lower part of the joint (the hull) was not flush with the upper part (the deck). For the remainder of the maybe 20 foot long part I examined, they were lined up perfectly (and sometimes still had cracks in the 5200):

uneven_joint1.jpeg

And here's a shot of a place where there was a crack in the 5200, and I cleaned it out with a utility knife to the extent that I could:

bad_joint2.jpeg

Since I've already cleaned it up, you can't see the original crack, but it was pretty obvious where rainwater was getting in, b/c it was pristine 5200 and then dirt inside the cracks. And here's a different area, after gooping up with 4200. I have to admit, it doesn't look like a very good job on my part, but after it had cured, I think I felt pretty good about the integrity of the joint.

gooped_joint.jpeg

After doing this along the entire stern joint (arch to stern to arch), I put the rail back on, injected 4200 into every (long) screw hole, put the screws back in, securing the stainless steel strip as I went so that I made sure it all lined back up correctly.

Jay
 
Jun 8, 2004
10,027
-na -NA Anywhere USA
Jay

I was Hunter’ largest small boat dealer for many years contributing more than anyone knows. My last message describes how hunter married the stern together. At times I was asked to teach other dealers on that technique plus as a point man traveling to repair them as described above.

If you want to find an easy method of finding topside leaks, be glad to share that ove
 
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Jun 25, 2004
475
Hunter 306 Pasadena MD
Dave,

Thanks for you offer of help. My repair is complete now, though, and I'm moving on to other boat projects which I have to complete before launching.

If correct, it would appear the boat was unprofessionally repaired. You should see pink material in the space between transom and the deck plate. There might be a Crack in the pink material.
It was designed the space between the deck and hull was filled with marine putty to the lip , sanded smooth with the back end of the boat with gel coat applied. That lip was above the waterline.
I'm fairly certain that our boat wasn't repaired, as we bought it new in 2004. Although I suppose it's possible they found a leak before we bought it.

Thanks,
Jay
 
Dec 19, 2006
5,809
Hunter 36 Punta Gorda
Crazy Dave should be very helpful.
My 2001 290 had a leak at the stern and lucky for me caught soon after purchase and Hunter paid for repair
and also gave instructions on how to repair to my marina.
I only had leak at stern and they took off rub rail and used wedges so could put 5200 in between joint top part
and bottom hull part and that was it but the dealer repaired other parts where hull joint leaked.
Good luck and Crazy Dave is excellent guy.
Dave doesn’t remember me but he helped give advice when I was first looking to buy a Hunter.
Nick
 
Jun 8, 2004
10,027
-na -NA Anywhere USA
Thanks @seadaddler. I am glad I helped you and many others. Of course I praised Hunter but highly respected for my stand when they were wrong. With one exception they did listen and even got upset a few times with me The exception was ACP construction vs my recommendation to build smaller boats out of fiberglass. I was elated when they changed over to fiberglass
 
Oct 14, 2017
89
HUnter 306 Aruba
Jay

I was Hunter’ largest small boat dealer for many years contributing more than anyone knows. My last message describes how hunter married the stern together. At times I was asked to teach other dealers on that technique plus as a point man traveling to repair them as described above.

If you want to find an easy method of finding topside leaks, be glad to share that ove
Crazy Dave - any chance you can share the method to finding topside leaks? I suspect i have some on my hunter 306.