1978 Sea Nymph SS160 resto

[Streetgang]

Re: 1978 Sea Nymph SS160 resto

Pretty baffling so to speak.

Firstly, congrats on the progress. I assume this is all outside work still and the Buick is still in it's resting spot.

Looks like you and trainman both have those boxed stringer if that is correct term, yet different models. Train and PMC appear to have more bulkheads, especially towards the stern. You have the 2 braces across the gunwales. Just wondering if there was some type of bracing or support po dreamed up?

Seems to me it was something very specific as 2 same same holes directly across from each other. But what would need a thru hull in 2 spots back there. Oh, congrats on the larger clear pics ! So staring at the hole I am thinking a plasma gun could cut that nice of a freehand hole, but why would they stop halfway done and peel it back on both sides. The they thru bolt some type of flange to hull.

Crazy....Maybe some type of hyper or warp drive that didnt work out.

Maybe an invite to Grandad to take a looksee would be interesting.

Speaking of him, a suggestion is that when you get the clean up done on the hull, get an adult beverage and slowly look it over closely for hairline cracks. Grandad had a good one and when I was done cleaning up mine, with a beverage happened to look down and yup, had a small, 4" crack. Fairly easy to fix, especially when all clean and open.

Hang in there ! Nice work.

 

[Streetgang]

Re: 1978 Sea Nymph SS160 resto

Got it,

It came to me in a dream last night. The po took it to a fab shop and described how he wanted guideons installed as they make recovery so much easier.

Problem is he didnt tell shop should be installed on trailer and they did it on boat !

Yup, crystal clear to me.

 

[Grandad]

Re: 1978 Sea Nymph SS160 resto

Maybe an invite to Grandad to take a looksee would be interesting.

You talkin' to me? It does seem to be consistent with improper trailer supports, depending upon exactly how uniform/symmetric the damage is. I note there is a drilled hole in the rib in line with the damage. Is there a hole in the rib at this point on the other side of the boat? If so, seems possibly intentional, like to secure some thru-hull hardware (a hydrofoil experiment or amphibious wheel attachment?).

Anyway, the welded repair looks competently done and is likely well sealed. The only attention I think you should give it is to get the inside as clean as possible and try to drive any moisture out from between the patch and the hull, perhaps with some modest heat. I'd then seal it well with something like Gluvit or thinned 5200. If water (even freshwater) is allowed to stagnate between the patch and the hull, it will turn acidic and start corroding the hull in a process called "crevice corrosion". - Grandad

 

[Watermann]

Re: 1978 Sea Nymph SS160 resto

Grandad, thanks for the advice on fixing the to pop tab holes carved into the hull.

To all who have a theory, well I'm leaning towards this was some secret experiment done at an area 51 type boat launch.

I was thinking I would dry out the holes real good, thump the tab back down with JB under it and if needed, finish the seal with some 3m.

On another note:
Progress will slow to a crawl for me now, I had to go in for surgery on a inguinal hernia earlier this week and right now my life has gotten painfully miserable. I have been shopping online tho...!!! boat parts in the ups truck!

 

[Watermann]

Re: 1978 Sea Nymph SS160 resto

Got it,

It came to me in a dream last night. The po took it to a fab shop and described how he wanted guideons installed as they make recovery so much easier.

Problem is he didnt tell shop should be installed on trailer and they did it on boat !

Yup, crystal clear to me.

It could very well be some sort of thought out thing but with what I see from the po who was very abusive to this poor little SN I'm thinking it was more like a repair for some sort of abuse or neglect. The bow eye was ripped through and weld patched. There's a stick or 2 of JB on the keel. Creased dents on the bow and now the area 51 pop tab holes. Oh yeah and the motor skeg / prop had also not gone unnoticed by the po.

 

[ezmobee]

Re: 1978 Sea Nymph SS160 resto

On another note:
Progress will slow to a crawl for me now, I had to go in for surgery on a inguinal hernia earlier this week and right now my life has gotten painfully miserable. I have been shopping online tho...!!! boat parts in the ups truck!

Been there, done that, the recovery sucks.

 

[Watermann]

Re: 1978 Sea Nymph SS160 resto

Firstly, congrats on the progress. I assume this is all outside work still and the Buick is still in it's resting spot.

Speaking of him, a suggestion is that when you get the clean up done on the hull, get an adult beverage and slowly look it over closely for hairline cracks. Grandad had a good one and when I was done cleaning up mine, with a beverage happened to look down and yup, had a small, 4" crack. Fairly easy to fix, especially when all clean and open.

Hang in there ! Nice work.

Thanks for the words of encouragement, I think I'm going to need them.

Well I was able to manhandle some bags full of Styrofoam and cleaned out the chunks with the shop vac today. I then took your advice SG and examined everything for cracks. The good news is the hull had nothing cracked the bad news is in the photos below. I have 3 ribs that are completely cracked through from one side to the other. One in the bow and 2 mid-ship and they were all on the same side.

Oh well at least it didn't flex enough to break a hole in the hull which I would imagine could have happened.

 

[Streetgang]

Re: 1978 Sea Nymph SS160 resto

Yikes,

Getting your more than fair share here.

Firstly, take care of yourself and make sure your healed up before getting on this bad boy again. As you mentioned good time to get that shopping list detailed.

These cracks always interest me moreso from the standpoint of trying to understand where the stress came from and if was more of a shock or just steady wear / tear or even bad design, under spec. material.....Obvioulsy something is going on there.

When the eather and your healing allows, you may want to get down on the ole hands and knees and crawl around in there looking for any hairlines where another split may be starting. Might as well get em all.

Repair:

I'm betting some pretty good folks will throw out some well thought out fixes so am confident you will have some good options and still an excellent long lived boat.

My 2 cents would be to also consider putting on some scabbing so to speak instead of the weld. Our shop has 15 welders / fitters who have to do aluminum, carbon and stainless. It is not repair but new production and the raw material is all about same 1/8" +/-. I have learned a few things over time which is welders are more like an artist and it is really a feel thing than mechanical. Also, cleanliness is absolutely critical. When going to a repair shop the welder / fitter generally is faced with a wide variety of gauges, materials, deterioration, etc. that make his job tough. I am just saying you need to feel very good about your welder.

So if welding is way to go then be sure area underneath, bottom of hull doesnt have any rubber gasket as will probably melt. Finally, a good weld will be stronger than original material, but a poor we

 

[jbcurt00]

Re: 1978 Sea Nymph SS160 resto

Many repair/weld shops won't work on old aluminum boats, esp not near seams.

PM Grandad since he didn't really comment about the questions posed to him earlier.

You may need to get some solid sheet stock under the rib bridging the crack, AND fabricate an upside down 'U' w/ flanges to match the contour of the rib & it's flanges. Then rivet the new 'rib' over the existing rib, thru the sheet stock & thru the hull..... W/ some liberal application of 5200/JB Weld to ensure there's no further movement of the existing rib or it's crack.....

 

[Streetgang]

Re: 1978 Sea Nymph SS160 resto

After I posted started thinking about what I offered and may have second thoughts.

With the ribs having to follow curve of hull it may limit putting the hat channel on top as it would be very stiff and not follow hull curve. Of course you could notch it along the way.

On other hand a long piece length of the whole rib and same width under existing rib say in standard gauge of .125 would follow curve easily and go gunwale to gunwale. All new rivets, easier to do and thinking it would be good to go.

Think I'll rest my brain now.

 

[Grandad]

Re: 1978 Sea Nymph SS160 resto

Many repair/weld shops won't work on old aluminum boats, esp not near seams.

PM Grandad since he didn't really comment about the questions posed to him earlier.

You may need to get some solid sheet stock under the rib bridging the crack, AND fabricate an upside down 'U' w/ flanges to match the contour of the rib & it's flanges. Then rivet the new 'rib' over the existing rib, thru the sheet stock & thru the hull..... W/ some liberal application of 5200/JB Weld to ensure there's no further movement of the existing rib or it's crack.....

As much as I appreciate the confidence you have in my opinion, I really am not experienced in working with aluminum. My "expertise" doesn't exist other than my experience with the problem that I tackled with my hull. What you have here is somewhat different, but I'll offer an unqualified opinion. The cracks in those ribs create points at which stress becomes concentrated (I think they call this a "stress riser") that likely has already flexed the hull skin substantially that may have work hardened the aluminum, even if no cracks in the skin are yet visible.

So, I like jbcurt's suggestion of placing some aluminum sheet between the cracked rib and the skin as well as re-inforcing the rib with a U shape or top hat profile. Streetgang has a good point that a repair to the rib will be stiff (another stress riser). The way I see it, you already have a stress riser, so as long as you try to spread the strength/stiffness of your repair, you can't go far wrong. Unless you can source a replacement rib, which is unlikely, you're going to have to compromise somehow.

I would use an oversized piece of aluminum sheet that would extend at least a foot in all directions of the crack and make my top hat repair to the rib somewhat shorter, perhaps only 6" beyond the crack. Whatever dimensions you choose, having the sheet aluminum extend well beyond the rib stiffener will spread the stresses somewhat like how a leaf spring might be assembled in steps. I don't know what the best extrusion profile would be for the rib stiffener, but I think I'd look for a rounded square tube that you can carve one side away into a U that follows the hull contour and then I'd have it welded it to the rib. http://www.extrude-a-trim.com/aluminum-extrusions/aluminum-tubing/telescopic/11 . I think it best to usually avoid welding, but I don't know how you can shape reinforcement to the rib and not weld it in place. I would still rivet and not weld any sheet material to the hull. It's gonna be a tedious task, but everything you do to rejuvenate this boat is a waste of time and money if the hull cracks after you're done. - Grandad

 

[Watermann]

Re: 1978 Sea Nymph SS160 resto

Thanks you guys for the thoughts on my broken rack of ribs. I now have some other ideas too besides welding that have come from your suggestions. I know I can think something up that will work and save the old girl from the scrap yard.

1. Replace and seal all of broken rivets in the area.
2. Use channel aluminum cutting it down to the hull curve extending out on both sides of the injured ribs.
3. Rivet channel to the injured ribs.
4. Using 2" x 1/8" thick aluminum stock create a "spring" by extending the stock over the channel rib repairs to the next unaffected rib, isolating the injured ribs in the center. Putting a small load on the channel.
5. Rivet down spring on top of unaffected ribs and top of channel.
8. I could even stack another piece of the stock to over the top of the springs and channel.

I would think this would effectively isolate and support the injured area from further damage and strengthen the ribs better than new.

Let me know if you don't understand my thoughts spewing forth of if you do and it's a stupid idea.

 

[jbcurt00]

Re: 1978 Sea Nymph SS160 resto

As much as I appreciate the confidence you have in my opinion, I really am not experienced in working with aluminum. My "expertise" doesn't exist other than my experience with the problem that I tackled with my hull. .............- Grandad

GD:
I could only come up w/ 3 'similar' rib cracks:
Your's
MagnumDeke's 1st project (ouch & yikes, and not a repair, more of a: 'Damn, wish it didn't end this way' solution)
RainbowHunter<<<---'wintering' in Mexico, and not currently active.......

So.......... Yes, you're somewhat similar rib cracks was as close as I could guess-ti-mate to being similar enough to be helpful. And more importantly, I knew you'd give a fairly great 'this is how I'd XYZ & this is why' response

Which is a great benefit of this site over others I frequent... Willing to help w/ more then yes/no responses & find multiple good solutions. Work thru the choices & try to avoid costly mistakes that put boats & boaters at risk, rather then often cosmetic only repairs.....

Keep us in the loop as you make a plan & get the ribs addressed :watermelon:

 

[jigngrub]

Re: 1978 Sea Nymph SS160 resto

Meh, smear some JB weld on it... it'll match the crapola in the bottom left of the pic and everything will be fine and symmetrical.

Just kidding of course.

I'd use .063 (1/16") angle on top of each rib flange and bedded in with marine epoxy and riveted in. Then fabricate a channel out of the same angle and cap the afore mentioned angles. I'd make each piece of angle about 2' long or whatever will fit and conform the best.

The .063 angle should be easy to work with and should conform to the curvature of the boat without much stress if the radius isn't too sharp.

It'll look something like this:

While the .063 will be easy to work with, when you get every thing fastened up your repair will be 1/8" thich on each side and the top of the rib.

This may or may not be suitable for your application... but it's what I would do, or at least try.

 

[Watermann]

Re: 1978 Sea Nymph SS160 resto

Meh, smear some JB weld on it... it'll match the crapola in the bottom left of the pic and everything will be fine and symmetrical.

Just kidding of course.

LOL, yeah for sure the po did have a love affair with destruction and goop, to include silicone and JB.

Thanks for the input grub. It seems pretty universal that the answer isn't to just have a weld slapped on it and start decking over. I think I will use marine tex or JB to bed the pieces, a little over kill never hurts.

 

[Watermann]

Re: 1978 Sea Nymph SS160 resto

Had a friend come over today to help me do some repairs on the ribs. I took 3/4" x 1/8" aluminum stock and cut it down to 6" strips. Then used SS bolts, nylock nuts and washers. 3M 5200, locktite marine epoxy and put them all together using the epoxy to bed the strips as well as seal the crack to keep crud out. After looking at the repair, I'm pretty sure it's stronger than original rib would have been. I decided less was more and fewer holes drilled in the ribs were better. It should take the pounding waves have to offer and then some. I may put an access hatch over the repair just for peace of mind and to check on it later on. For now I'm thinking doing this repair and replacing a bunch of broke off blind rivets around the site will yield a strong repair.

I guess time will tell, now I have the bow rib to fix on another day.

 

[64osby]

Re: 1978 Sea Nymph SS160 resto

Nice solution to an ugly issue. Looks solid.

 

[Watermann]

Re: 1978 Sea Nymph SS160 resto

Got the entire mega tube of clear silly cone out of the inside of the keel. On the outside of the keel the po had built up a cruddy looking wad of JB so I knew there was a problem. Here is a pic of what I found underneath the goop.

A crack, 2 holes that I could see through and a bunch of deep nasty corrosion pits that are almost through. Looks like the po had been keel hauling cinder blocks. :laugh:

 

[jasoutside]

Re: 1978 Sea Nymph SS160 resto

Nice digging and good find (well bad find, but you knowhattamean).

 

[Streetgang]

Re: 1978 Sea Nymph SS160 resto

If possible would like to see pic of same area on outside. Wondering how bad the keel has deteriorated. Might help everyone.

For kicks did an advanced search on "cracked aluminum keel" and quite a few hits, suggestions, repairs.

Obvously can drill and stop the crack but from there it will be very interesting to see what suggestions come out.

You could shape a piece of 5052H32 alum. to fit into the area. Some combo of gluvit, gflex, 5200 would come into play between the patch and keel. Fastening it might be straight forward if you hit the flanges of the keel on outside ??? May want to make that piece a bit on loose side along edges....not sure on that part. The epoxy / 5200 would seal the gap.

I'll be following with interest.

Have you had your surgery and still doing all this stuff, let alone working outside ?