72 Starcraft 16' alum, holes in keel? old patches

[Old Ticker]

I've been lurking for days, we have a 72 16 ft alum Starcraft, was a Supersport we learned from looking on Ebay but was stripped down long before us. We're 1st time boat owners and tried the boat out and all that but we decided before we get it to the lake we'd pull up the "just OK" ply flooring to see just how many leaky rivets were there. We filled bottom with water after much cleaning, about a dozen rivets leaking, they've been patched previously with some tan goop that isn't as hard as I think JB would be unless it getting wet repeatedly would cause it to have some give. I know from reading on here we should clean all the old patch from rivets inside hull, clean thoroughly and use Gluvit, right? We were going to have it welded but after reading on here, we decided bad idea. The leaking is not horrible so the old patch jobs and goop on the rivets is holding for the most part. They just need maintenance, the keel (not sure that is even right term, see pics) point is the bad leak. Our main concern is what I've taken pics of and included. The keel has a bad patch job where I guess someone beached it on a rock or something at one time. There also appears to be some oxidation holes. We are clueless how to proceed with this repair?? I've been unable to find out on the forums thus far. Forgive me if its here and I just didn't find it. Thanks to anyone with advice! Bill Jackson

 

[Bob_VT]

Re: 72 Starcraft 16' alum, holes in keel? old patches

Hmmmm....

Welcome to iboats! HA HA another Starcraft person

Well first I would get rid of the old goop with a wire brush and get those corroded areas clean.

That leak almost looks worn through! I would consider some cleaning and some JB weld or grey marine tex to fill the area and reshape it. Once that is done I would use gluvit on both the inside and outside on that spot.

It appears to be a tough spot to fill and build with welding

If you are in this deep I would bite the bullet and re-do the plywood floor too. Spend the time and do all the repairs it needs and you will never look back

There are MANY MANY MANY aluminum Starcrafts and owners here who will help out.

Once again welcome to the Starcraft armada

 

[Old Ticker]

Re: 72 Starcraft 16' alum, holes in keel? old patches

Thanks Bob, I'll add a few pics and ask a few more ques. Some pics are outside bottom of boat behind bad keel point, you can see some bald spots where the paint chipped away. The old paint is about as thick as 3 sheets of paper. We (yes we, this is the wife, I'll be working too) were going to sand and feather into old paint, use ZC and then touch up spots with oil based rustoleum, we aren't ready to paint whole boat bottom or top for that matter, we want to get out on water and see how this boat fits us. Also there was a shallow dent about the size of 2 footballs on the outside of the bow, 2/3 way up to top. Bill beat it out from inside with a shop hammer, now all you can see is ripples. Not bad but they're noticeable and we aren't sure when it comes time to paint how to repair that area. Bill is a perfectionist when it comes to body work, so I dread it! I'll post pics when time for that project comes. Anyway won't worry about that for now. I'm reading on here just use the standard 4 1/2" wire wheel either on a drill or a grinder? Does it matter?
There are also pics of the inside of the bad keel point area, where they've put tan goop and then some clear shiny almost rubber coating over goop. I'm wondering if it's old Gluv It. Some pics of bottom of boat, showing the goop over the rivets. I'm reading on here and saw jlowmillers thread, I see where we need to use a soft touch with the wire wheel. We will use the same wire wheel clean up method on the bottom inside of boat to clean off goop from rivets and the bow point right? Will 1 qt of Gluv It be enough, from what I've read it will be? We understood to use it all over cleaned bottom inside, and also over the JB Weld or Marine Tex patch on the outside keel patch? Thanks anyone and everyone for all the great info on here and any you send our way! Elizabeth Jackson

 

[Bob_VT]

Re: 72 Starcraft 16' alum, holes in keel? old patches

It could be gluvit. Gluvit dries amber in color and VERY smooth. It levels out by itself like a puddle of water. It is like a super hard rubber.

Yup a wire brush on a drill is great and if you use a grinder with a wire brush thay can eat aluminum. You can sand what you have smooth and apply gluvit over it if it seems secure and paint over that.

Yes you can use jb or marinetex outside the hull just feather it in and make sure it is sticking to clean aluminum.

1 Quart (it's just the size of the can it is sold by weight) will be plenty.

 

[Old Ticker]

Re: 72 Starcraft 16' alum, holes in keel? old patches

One more quick que, I found some stuff locally thats called PC 11 Marine Grade, it is for bond, seal, and fill, all metals, fiberglass, PVC, Tile, Boats etc. it says no sag-no drip-no shrink says it contains epoxy resin and hardeners, you ever heard of it? I'm ordering Gluv-It, so I can order the marine tex, but this stuff seemed to fit the bill. It seems I read the name somewhere on here, but can't find it now. Just wanted to know if anybody has used it with success or failure. It would be going into the keel area, building it up before the final coat of Gluv-It. thanks E Jackson

 

[Bob_VT]

Re: 72 Starcraft 16' alum, holes in keel? old patches

PC11 is the marine grade and is not too bad. It's kind of thin and is similar to jb weld except it is white/gray. I have used it but not on aluminum.... I think it should work.

Marine tex http://www.iboats.com/Boat_Parts_Ac...**********.650478136--submit.x.33--submit.y.6

 

[Old Ticker]

Re: 72 Starcraft 16' alum, holes in keel? old patches

Sorry one more thing, I read on here to replace missing rivets with #10-24x 1/2" SS screws, we have a few rivets holes that are above water line, and may have one or two more down below I haven't cleaned off yet. He said to use truss head phillips screws with flat washer, and nylon locking nut on back side. A drop of sealant on each screw head also. Nobody around here knows what "truss head" screw is referring to, can anyone tell me? Also can i use a drop of gluv it as the sealant on each screw? thanks a bunch! E Jackson

 

[sschefer]

Re: 72 Starcraft 16' alum, holes in keel? old patches

Sorry one more thing, I read on here to replace missing rivets with #10-24x 1/2" SS screws, we have a few rivets holes that are above water line, and may have one or two more down below I haven't cleaned off yet. He said to use truss head phillips screws with flat washer, and nylon locking nut on back side. A drop of sealant on each screw head also. Nobody around here knows what "truss head" screw is referring to, can anyone tell me? Also can i use a drop of gluv it as the sealant on each screw? thanks a bunch! E Jackson

You can order truss head machine screws through West Marine or Fastenal.

Do not use a washer on the head side of the screw, that's why you are using truss heads. You should use one on the inside. You should also use a dab of 3-M 4000 sealant around the flat side of the head. Do not use an impact driver to tighten the screws up. You can easily snap them off or ding up the head so bad you'll have to drill them to get them out.

The location of your problem is not one of high stress. They don't double rivet it there and the part that is worn through is acutally a cap. I'm pretty sure you could have that welded and patched or filled without having to worry about cracking the hull. Normally I wouldn't recommend it but in this case it might be the best solution.

Do not use durafix or hts2000, those require you to heat the material to 732degs and that will warp your tempered aluminum hull.

For your hull dings and dents, use a heat gun set to 400 degrees first. Just heat the area evenly and then watch what happens. Often in the case of a dock ding or a push dent, the aluminum will try to get back to its original shape and most of the dent will disappear. If it's a crease or a dent that appears to be extruded (stretched) then you need to remove the extrusion because no matter how much you beat on it you will never get it to look right. In many cases a marine grade, bondo like, aluminum filler (3-M makes one) is the best solution.

 

[Old Ticker]

Re: 72 Starcraft 16' alum, holes in keel? old patches

Thanks for the info, as usual I have another question. I'm out there in the bottom of the boat wire wheeling the gooped over rivets when I realized the goop is indeed JB Weld. Now Bob said in one of his earlier posts that after we built up the keel repair (if we don't weld it), after the built up area is dry then coat it with Gluv it. He mentioned JB Weld in his post for that area. So my question is, is it necessary to completely grind (with wire wheel) all the JB weld off of rivets inside bottom of boat, because in getting it all off, its grinding the rivet heads smooth & rounding off their heads. Can we just knock the top layer off exposing the rivet head and after properly cleaning inside boat bottom, coat with Gluv it? Or must they be ground to a nub clean? I've included pics of my rivets, also one from front to back of inside floor, and one of the dented/beat out area. Thanks again, E Jackson

 

[Bob_VT]

Re: 72 Starcraft 16' alum, holes in keel? old patches

The gluvit will adhere to the jb weld. Just make sure you have it clean like in the first picture.

 

[sschefer]

Re: 72 Starcraft 16' alum, holes in keel? old patches

The gluvit will adhere to the jb weld. Just make sure you have it clean like in the first picture.

Exactly.. I usually sand the JB or Marine Tex and surrounding metal with 80 grit just to give it a little extra grip. The wire brush will make it shinny but that's a burnished shine and not the best for adheasion.

 

[Old Ticker]

Re: 72 Starcraft 16' alum, holes in keel? old patches

Cleaned out most of old patch job, gash is about 6 inches long and at one place I've not been able to get the wire wheel on up into hole to clean what appears to be bondo, but could be thick JB Weld. I added a few pics of what it looks like now. The gash starts about 6 inches before the keel point cap ends, and ends about where it attaches to the flatter plate rib that goes the whole length of boat. This "cap" has 2 rows of double rivets down either side. The gash appears to have loosened the seams around the rib directly above inside the boat, and from there probably caused several rivets in general area to seep/leak. So I really like the welding idea, after seeing it with some clean off done, any more comments on best fix? Thanks Bill

 

[Old Ticker]

Re: 72 Starcraft 16' alum, holes in keel? old patches

By the way, after looking over the pics, that isn't all aluminum up in the worst of the hole, part of it is a gray filler of some sort. I guess I'll get the dremel tool up into the crevice, or should I just leave it for the welder? It apparently is the keel shield, the hole appears to be deep enough to reach where the 2 sides of the boat were put together.

 

[sschefer]

Re: 72 Starcraft 16' alum, holes in keel? old patches

O.K. If there's double rivets, don't weld. That's hardened aluminum at those joints and it will crack if you do anything more than tack weld it. A lot of welders will say they can weld it but a real boat shop will tell you no. The problem is that the cracks don't show up until after you've had it on the water a few times and the way that aluminum disperses heat, it's hard to tell if the welding caused the problem or not. It did, you can trust in that.

Is there any way you can see to patch it. The common method is to form a piece of aluminum over the affected area and then place a piece of rubber gasket between it and the hull a rivet it on. I just had 12" gash in my bow fixed that way.

 

[Bob_VT]

Re: 72 Starcraft 16' alum, holes in keel? old patches

I am still of the same opinion here. Marine tex will build and repair that spot. I would not weld that spot. That's a place that will continually take a beating and marine tex covered in the end with gluvit will fix those leaks. That is not really an area that will flex while under power.