Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

[appleo]

17 foot starcract...keel has crack.....need advce on repair option. Thanks

Danny

 

[lokonn]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

I'd say find a welder that knows how to weld aluminum. My understanding is that if not done properly can re-crack due to over-heating. There are a lot of people on here that have different ways to "skin the cat" though, and they have a lot more experience than I. I'm sure you will get more info as more people see your question. Good Luck.

 

[kfa4303]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

I agree that finding a good aluminum welder will be your best bet. In the mean time, you should drill a small hole at both ends of the crack to prevent it from spreading any farther.

 

[lokonn]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

I agree that finding a good aluminum welder will be your best bet. In the mean time, you should drill a small hole at both ends of the crack to prevent it from spreading any farther.

I second the stop drill of the crack. Will be doing that before I patch up my hull.

 

[SigSaurP229]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

Depends on how pretty it needs to be.

If it were me I might consider drilling both ends of the crack to stop it.

Then I might buy and bend some aluminum plate fit in the keel seal the back side of the plate with some 5200 between the plate and the hull. I would then use closed end blind rivets to rivet that plate to the hull I'd cover the back side of the plate in GLUVIT and fill the crack with JB WELD on the outside.

EDIT

Never mind that looks like a major crack.

You need a GOOD welder.

If not welded properly it can recrack and if not welded properly it can warp the aluminum as well.

 

[ilovevintage81]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

You dont really have to do all that but jb weld you will need put like 1/4 inch jb weld on inside two to three coats then take file to outside fileing crossways not along the crack and eventually you wont even see crack try to smash the weld through from inside just before filing with metal file all the filed particles should fill up hole after hardening sand outside then paint another coat weld inside and i bet water wont leak unless you hit in same spot you could even seal inside ontop of weld with some marine sealent or silicone jbweld will be enough as long as you put enough just dont put on outside you shouldnt even notice it after sanding

 

[classiccat]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

I'm in a similar situation where the PO ground-down a few feet of Keel by running the boat on metal keel roller shafts.

Originally I was going to have it welded however I've since changed my mind since I don't know of a good welder and excessive heat could do more harm than good (if the existing rivet holes expand -> leak).

Inspired by an old iboats thread (i'll see if i can dig it up), I've since ordered a sheet of 6061 aluminum from which i plan to shape, cut and rivet to the keel. I'll add an adhesion layer (JB or MarineTex?) so that I get strong mechanical coupling between the retrofit and existing keel.

 

[classiccat]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

I like the solution in Post #2.

 

[NoSkillz]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

I say get a rivet set and bucking bars and get to work!

 

[kjdunne]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

To BlueFin16 post #7, I'd use 5200 for the sealant / adhesive between the patch & hull.

 

[classiccat]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

To BlueFin16 post #7, I'd use 5200 for the sealant / adhesive between the patch & hull.

:thumb:

 

[ilovevintage81]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

Jb weld only unless you want to spend alot then you will have ribits everywhere and wont look good

 

[ilovevintage81]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

If jbweld will seal outside of a head and manifold i belive it will do the job on that

 

[NoSkillz]

Re: Riveted Aluminum Hull - Keel repair needed/cracked up front. - need advice

Jb weld only unless you want to spend alot then you will have ribits everywhere and wont look good

Aircraft have rivets everywhere and they look fantastic... Countersunk rivets and a little polishing and it will look OEM. It would need sealing but those materials already exist so you wouldn't be reinventing the wheel.