Chine reinforcement?

[crabara]

I have a 1975 18ft ss I am rebuilding, I have seen from doing research that the 70's starcrafts have been prone to cracking in the chine. I was just wondering if anyone has done anything to reinforce the chine or just leave it at is.. there is no cracking on my chine, just looking to see if anyone has done any mods to reinforce this.

 

[ezmobee]

Re: Chine reinforcement?

Do you have yours torn apart yet? Cuz my '76 already has reinforcement added from the factory. http://i176.photobucket.com/albums/w200/ezmobee/New Boat/DSCF2259.jpg

 

[Chinewalker]

Re: Chine reinforcement?

A guy I worked with years ago at a Starcraft dealership told me it took Starcraft awhile to figure out why the chines were cracking. Come to find out, it was thought to be due to the workers scoring the inside of the chine with a carpet knife while they were installing the carpeting on the floorboards. The scoring created natural weak spot and some of the hulls would crack there after a number of years of use and abuse...

 

[magnumdeke]

Re: Chine reinforcement?

My 69 Islander was cracked on both sides, it had no reinforcement and also a lot of the rib ends were cracked some right thru the hull.
inside of chine previously repaired

rib end cracks

those problems caused me to scrap that hull, by 1976 there is this reinforcement in the hull to prevent that
if you look to the side of my sons hand you will see the chine is covered by a piece of aluminum that goes up the side above the chine and under the rib ends

my belief is that no matter the hull aka SS or mariner or whatever. if the chine is open that it would be prudent to drill out the rivets at the rib ends and have a piece bent up to mimic what starcraft did to cure this and install it, especially if you are like a lot of us who are dumping money into old boats with the intention on keeping it. I am doing my boat in the belief I will never get my money back, but I will have a basically new boat paid for in cash. No way that would happen for me with a truly new manufactured boat, I would not get a loan to buy one. That is why we do what we do, so if the boat you get or have needs this reinforcement and is not cracked take the time and do it knowing it will work. Inspect any of the Starcrafts to make sure they are not cracked, in my mind it is not worth fixing the cracks and woryring about it happening again.

 

[Gibbles]

Re: Chine reinforcement?

crap!

good info, wish I knew this before I got my floor installed :facepalm:

Hopefully 60's starcrafts handle it a lil better...

 

[Grandad]

Re: Chine reinforcement?

I have a 1975 18ft ss I am rebuilding, I have seen from doing research that the 70's starcrafts have been prone to cracking in the chine. I was just wondering if anyone has done anything to reinforce the chine or just leave it at is.. there is no cracking on my chine, just looking to see if anyone has done any mods to reinforce this.

Hi crabara, my '72 Holiday 21' originally had no reinforcement. As far as I know, my chines weren't cracked, but the hull sure was. I reinforced the hull (and I suppose the chines) by adding a stiffener on top of the ribs. Details are in my rebuild thread linked in my signature, but here's a couple of pictures. - Grandad

 

[elkhunter338]

Re: Chine reinforcement?

I have heard about this, but finally saw these pictures. Thanks. It shows me were to look if I ever look at buying another starcraft or I have the floor out of mine again (hope not). Now I see why a friend of mine said these boats never survived well in Alaska, they could not take the abuse.
Make me still think about building my own boat, a Renn tolman Alaskan Skiffs (Widebody or Jumbo (plywood/epoxy/fiberglass)). we will have to see what my future holds. Hopefully the old Cheiftain will hold together.

 

[barato2]

Re: Chine reinforcement?

aieeee, this is what i get for reading. after all the other reinf i'm doing on my hull, guess i need to do this too. EZ, i notice in your pic that it seems to only cover the rear half of the hull, from where the side panels begin? is this true of all factory reinf?

 

[barato2]

Re: Chine reinforcement?

bump

anyone have any input on what portion of the hull (lengthwise) the factory reinf covers?

also, since my floor will be riveted in solidly to stringers and ribs, is there some reason i couldn't rivet the reinf to the TOP of floor?

thanks!

 

[jbcurt00]

Re: Chine reinforcement?

since my floor will be riveted in solidly to stringers and ribs, is there some reason i couldn't rivet the reinf to the TOP of floor?

Isn't the reinforcement 'plate' going between the rib & the hull? How would you rivet it to the top of the floor if it's under the rib?

Sorry no other input

.......

 

[Gibbles]

Re: Chine reinforcement?

I also wonder if just having a stiff floor + solid side pannels would also help...

I have a different hull type so I'm hoping i'm ok, + this thing made it over 50 years with out any issues.

I doubt it will ever see water rough enough to even matter since I'm land locked too...

 

[Grandad]

Re: Chine reinforcement?

barato2, I can't provide dimensions of Starcraft's reinforcement length. From what I've seen in the Iboats forum, there have been at least 2 methods. One is a lengthy L shape riveted under the ribs and to the side of the hull. The other is a series of L shaped tabs perhaps 3" wide riveted under each rib and directly to the hull. The fix that I used pictured in post #5 above uses an 8' long L shape that sits on top of the ribs, is riveted to them in a sandwich with the "floor" plywood. In the picture, it is slid toward the stern exposing new added flotation. 8' suited the length such that I could also rivet the sidewall verticals and the shelf into a solid box structure. The plywood sidewalls are then tightly wedged from the gunnels just as Gibbles has suggested.

jbcurt00, I think you're right in that the best placement for the reinforcement is under the ribs next to the skin, but it may not be worth the investment if the original OP's hull is still intact. Barato, I think that riveting reinforcement on top of the plywood floor could cause the rivets to prematurely fail. The plywood sitting on top of ends of the ribs will eventually dimple, reducing the thickness of the sandwich and allowing the rivet to gain some play. Once that happens, a rivet's life expectancy is reduced.
- Grandad

 

[ctswf]

Re: Chine reinforcement?

oh goodness, Im about to do a floor on my 1969 offshore v, has no reinforcement, I supposed I should do this too:grumpy:

although, its been fine since 1969 and has no cracks yet.

 

[ezmobee]

Re: Chine reinforcement?

oh goodness, Im about to do a floor on my 1969 offshore v, has no reinforcement, I supposed I should do this too:grumpy:

although, its been fine since 1969 and has no cracks yet.

I don't think I'd lose any sleep over it. Just reinstall the side panels and I'm sure you'll be fine. The cracks I've seen in that area were generally the larger, heavier hulls.

 

[ctswf]

Re: Chine reinforcement?

Im going to take a closer look at it tonight, think I might just do that, with the side panels in place its been strong all these years...

 

[barato2]

Re: Chine reinforcement?

thanks everyone for info, esp Grandad. you're right that my idea is a half ahse way to do it, but my rivets are solid and already Gluvit'ed and i don't want to have to drill out good rivets, esp below waterline. i may try your over-the ribber and-under-the-floor approach. i assume you had to cut or rout clearance notches into the bottom of the floor for your reinf sections?

 

[Grandad]

Re: Chine reinforcement?

i assume you had to cut or rout clearance notches into the bottom of the floor for your reinf sections?

Nope. I had the aluminum sheet bent to about 85 degrees (they mistakenly bent them to 90, but I adjusted them easily) so that they fit the sidewall angle and also fit flat under the flooring. I used the original 1/2" plywood, so the increase in thickness was only about 1/16". The inner edge of the gunnels must have risen slightly (1/8" including my hull patch) when I pressed the original sidewalls back into position, but there's no discernible difference in appearance. Tight is good. - Grandad

 

[barato2]

Re: Chine reinforcement?

cool! thanks again for your time and input. i already have my floors cut n epoxied in 3/4" so i'll have to live with that. but i haven't mounted or drilled side panels and don't have an issue with consoles to line up.

i'm wondering if i'll need to put a shim of same thckness as my braces between tops of stringers and floor so floor will lay flat, but that can't be too hard. i already have a bunch of .100 thick 6061 so i think i'll bend bracing up out of that.....i may have to do "tabs" like the second factory version instead of your solid panel to make my aluminum go far enough.