starcraft sea mist hull repair (cracks)

[Furrylittleotter]

You would need to remove every rivet from the braces, remove them, have them tig welded inside and out, then reinstall them. The hull patch would go inside the hull and since its buttered with 3m 5200 it does not have to contour to the pseudo lapstrake. 5200 will fill the voids.

Neil

 

[bunnymoney]

No Title

I would not repair the cracks in the ribs at all. I would tie both ends of the rib together with an aluminum strip all the way across the hull ( look like a bow string ) and be sure to attach the deck to the strip in several places to prevent it from bowing. In effect you make an ugly triangle that will not budge. You must stop the flexing.

I still don't know how the bottom flexed to cause the crack on the strake. Figure this out, then proceed.

Maybe someone has seen this before.

Don't come to me for advice on your windshield. I tossed mine and tore up the bow deck and now I have this:

 

[jbcurt00]

Dont pull tubes w a ski pole, skis and wake/knee boards only.

Lots of suggestions to consider, give them all throrough consideration and proceed however makes the most sense to YOU and fits your fabrication skills.

Digging thru other rehabs of any tin boat, not just SCs and her clones will help ya figure out what method firs best w the repairs you need to make.

I suggested an exterior patch so that could extend beyond the rib the crack runs up to or under. IMO, the faux lapstrakes are large enough to need bending the patch to follow the lapstrake contour.

An aluminum half pipe and angle have been used to bridge over rib cracks similar to yours. I suggest doing that and securing new decking to the rib ends as the cross tie (a 2ndary angle or aluminum strip may do it better but well secured plywood would do it too [did originally from SC]) and the center stringer.

Soft decks and side oanels combined w running rough all likely contributed to the chine crack. Common occurence on the 18ftrs and up from the 60s and 70s. Later boats had a factory added rib end tab to help prevent chine cracking. Watermann fabbed DIY tabs on his SS and/or Chieftain, to prevent it. Cant recall which offhand...

 

[xjdriver]

An aluminum half pipe and angle have been used to bridge over rib cracks similar to yours. I suggest doing that and securing new decking to the rib ends as the cross tie (a 2ndary angle or aluminum strip may do it better but well secured plywood would do it too [did originally from SC]) and the center stringer.

hmm I like this idea

 

[bunnymoney]

This crack is not on the chine. It is in the middle of the hull on the edge of the formed lap in the green circle. Does anyone have pictures of similar cracking?

click here VVV

 

[xjdriver]

This crack is not on the chine. It is in the middle of the hull on the edge of the formed lap in the green circle. Does anyone have pictures of similar cracking?

click here VVV

I did see someone with a similar crack in the re build section, the crack was on the splash rail, apparently he just used gluvit. i cant seem to find the thread tho. I will be making, (or at least attemting to make) a patch panel for mine from the outside like jb suggests.

well looks like its time to start putting a list of stuff together, a lot of 5200, rivets, goof off, rivet gun, (any suggestions on a good rivet gun)?

also Im not sure on the size and type of rivets i'll need , I read in the forums 3/16 closed end blind , and in different lengths.Im guessing all alluminum.

 

[bunnymoney]

Since you have access to both sides use solid rivets like all the other rivets in the bottom of your boat. Closed end blind rivets when you only have access to one side. My boat has 3/16 solid on bottom and 5/32 blind and 3/16 solid on the gunnels.

 

[mbroughton02]

Yes use solid rivets. Many of us have set them with an inexpensive air hammer from Harbor Freight with the pressure turned down to about 60 or so. You'll need to buy a rivet set for the air hammer that matches the head of the rivets. I used brazier head in both 5/32 and 3/16 diameters, and I needed 3/8" and 7/16" lengths.

 

[Watermann]

That's a interesting crack that the boat has developed, not sure I've sen one in that location before. I've repaired some cracks and as said welding is not the best way of repairing it but it can work if the reason the crack formed is addressed. Most of the time an added patch over the crack takes the stress off. In your case with that lap right next to the crack it will be difficult but not impossible to duplicate the curve to properly attach the patch. You never want to weld a riveted boat near a seam but in your case it's not a seam and you could have the 4" crack welded up and then patch over it. Never use blind rivets on the bottom of a boat or below the waterline, they are fragile compared to solids and will not take an impact very well.

Splinting or bracing over a cracked rib as you have is the accepted way of repairing the cracked ribs. Basically you have to cure the reason the crack formed and then repair it by adding bracing that will take the stress off the damage so it doesn't keep cracking or re-crack. In your case a boat well powered with a 70 and then used with compromised wood in the boat that adds greatly to the structural integrity.

A hull becomes sort of floppy without everything inside being at or near 100% and is a good way to ruin one of these boats.

 

[xjdriver]

Thanks for all the good info guys, didnt really get much done on the boat last weekend. I did put a carport up so I dont have a flooded hull to work in all the time. I did start drilling the center stringer rivets and some just want to spin, any easy way to stop them from spinning?

 

[Watermann]

Thanks for all the good info guys, didnt really get much done on the boat last weekend. I did put a carport up so I dont have a flooded hull to work in all the time. I did start drilling the center stringer rivets and some just want to spin, any easy way to stop them from spinning?

You can try a couple different methods of removing the heads off the blinds, either with a steady hand using an angle grinder or go old school is my preference with an old wood chisel sharpened up and hammer to tap and cut them off. Then use a punch to drive the rivet body out of the hole.

 

[xjdriver]

some progress... also got some alluminum tubing to put over the cracks. next step is finding a welder. I think im also going to have the hull crack welded, like watermann said its not near a seam.