1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill them?

[Longhorn90]

Hi-
I bought my first boat last weekend. A 1981 Lund C-14 (14ft). Excited to take the kids fishing, and it will also be used for water rescue training for our Newfoundland dogs.

Seemingly good condition for being that old, came with a trailer and a nearly unused (even though older) Mercruiser 8HP outboard. The owner I got it from seemed perfectly honest and said he and his son had taken it out and had zero leaks (and I know where to find him Anyway, my reason for posting......

I haven't had it in the water yet to confirm it doesn't sink because I've got the trailer (nice condition 1982 Calkins....seemingly overkill w 3x3 tubing and rollers and bunks, yet only 1600lbs rated?) up on jacks while I replace the hubs and springs so I can go long distances with peace of mind.

So, my question to any experts out there is, do small gaps between rivets on the outside of a side seam mean problems? Assuming they don't leak, is it something that should be filled (gluvit or 5200 have popped up in searches as possibilities). The inside of that same seam is perfectly flat, with no gaps, and couldn't stick a razor blade between aluminum panels that are joined by that seam!

Heres a photo of the outside..

 

[Longhorn90]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill th

Anyone?

 

[Georgesalmon]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill th

not a problem, there is some sealing tape between the seam under the rivets

 

[jigngrub]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill th

Even if they didn't leak I'd fill them with something just to keep trash out.

 

[Georgesalmon]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill th

He's right, if sand/dirt gets in there it can destroy the seal.

 

[Longhorn90]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Thank you! Thats what I was hoping.

As for sealing the gaps, would Gluvit, 5200 or something else be best?....easiest to apply in this situation?

Is one product more forgiving of existing sealant residue in these gaps and/or will one play better with the sealant that is in the neighboring, non-gapped areas that I'd have no chance of getting at whats already under there? Guess I'm questioning quality and longevity of results versus effort...

Any tips would be much appreciated!

 

[jigngrub]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Gluvit will work, but you'll have to paint over it because of UV breakdown. 5200 would probably be your best bet.

It may take several applications to fill the gaps completely, the 5200 will "run" down into the gap. Let each application cure before starting another one

 

[Georgesalmon]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

5200 would work but it takes 7 days to cure in the standard version. My son owns an AL boat manufacturer. They use a grey colored sealer there at the factory to kinda match the aluminum color. I'll call him today and ask what it is.

 

[jigngrub]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

5200 would work but it takes 7 days to cure in the standard version. My son owns an AL boat manufacturer. They use a grey colored sealer there at the factory to kinda match the aluminum color. I'll call him today and ask what it is.

That's the blue label 5200, the red label setsup in 24 hrs.

 

[Georgesalmon]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Can't find the "fast cure" red lable around here. Wish I could. I find that a little spray of water does help a little but not that much.

 

[Longhorn90]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Georgesalmon- Thanks! If you could find out what that gray colored sealant is that your sons company uses on Aluminum boats that'd be much appreciated.

Per a chart I found, the fast cure 5200 only comes in white which would potentially look like a bad pinstriping job against a bare aluminum boat

 

[jigngrub]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

If you want something gray there's the Loctite marine epoxy 15 minute formula, it would actually be the very best thing to put in there. Extremely tough but flexible.

I haven't suggested it until now because it is a 2 part epoxy that you have to mix and obviously work fast with it. It would have to be applied with something like a small plastic putty knife.

You can find it online for about $3 for a .85 oz. tube and would take 4 or 5 tubes to do your gaps.

I've used this stuff on some small holes in my boat and when installing closed end blind rivets.

 

[Georgesalmon]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Sorry, its a Silane terminated polymer. Whatever that is,,,,, They get it 55gal drums and have an air operated pump to a gun that applies it. Cures fast, adhers well, UV resistant. Unfortunately I don't think you can get it in small quanties. Probably better look at the epoxy jigngrub suggested. Flexibility is important the hull will move and flex a bit..

 

[Longhorn90]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Thanks everyone.

Unfortunately the Loctite Marine Epoxy only comes in white. There metal/concrete version comes in gray, but that isn't flexible.

Probing on the internet has led me to a few other readily accessible possibilities that am wondering if anyone has thoughts on:

Sikaflex 221 (or the 227 fast curing version) comes in gray. The 221 seems to have more flexibility than the 227 per their spec sheets. Sold by Jamestown Distributors online.

DAP Premium Polyurethane Concrete & Masonry Sealant (UPC 70798 18814 or 70798 74816). Sold alongside their other marine caulkings at Jamestown Distributors online. Haven't found locally yet. DAP's Tech Bulletin specifically mentions it adheres to Aluminum and is a watertight, weatherproof, flexible seal. Although does say not for below waterline applications (although myboat does not stay in water).

DAP Concrete and Mortar Filler and Sealant (UPC 70798 18021). Sold at Lowes and Home Depot. Flexible, waterproof, weather resistant seal and resists UV. Resists Gas, Oil, Grease and Salt. Tech Bulletin says outstanding adhesion to 'other construction material' which a call to DAP yielded that includes Aluminum. Again, says for best results not for 'below waterline applications'.

Thoughts or experience? (And sorry if I'm making too big a deal out of filling a few gaps...)

 

[Georgesalmon]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

FYI, my son came over last night and he said they don't even use anything on those joints anymore. The other day he just answered my question about the sealant they used to use. His company stopped using it several years and has expierenced no warranty issues or repairs They were still using it when I was plant manager but that was over 15 years ago and I didn't know they stopped. Sorry about my bad information. If I were you I wouldn't worry about it unless it is a cosmetic issue for you.

 

[Longhorn90]

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Re: 1981 Lund C-14 Aluminum Boat - Will gaps on outside seam cause problems? Fill?

Georgesalmon, thank you for all your help. Not really needing to do anything is an ideal situation. Yes, I'm rather detailed on most anything I have/do, so I'll probably fill it just for the mentioned cosmetic reasoning. And being overly cautious, I also figure I'll seal it just because what was said earlier about keep grit and things out of the seam to avoid possible harm to any inside seam tape or filler seemed logical. I'll just do this with a little less concern over exactly what product I use...probably leaning towards the DAP sealant I can pick up right at Lowes/HD.

Thanks again to everyone who chimed in.