Islander 36 Keel Bolts (cont.)

[Found at Sea]

Earlier I asked about an unusual configuration of keel bolts where only bolt heads were exposed. Thank you all for your many responses which , along with a survey, prompted me to not buy that boat. I am now considering another I36 which has the original keel bolts but they are in very poor condition. After speaking with several I36 owners their recommendation was to break off the nuts with a cold chisel, rethread the bolts (studs) a size smaller and install new stainless washers and nuts. My questions are: Has anyone used this fix for corroded keel bolts and, will there be an issue using dissimilar metals (mild steel bolts and ss washers and nuts?

Thanks in advance for your advise.

[jongleur]

My first thought was, "Wow, that's a lot of keel bolts."

36 of 'em.

[Terra Nova]

Originally Posted by Michael Ramos

...several I36 owners their recommendation was to break off the nuts with a cold chisel, rethread the bolts (studs) a size smaller and install new stainless washers and nuts...

The designer thought he made the right choice as to size and number of keel bolts. Who do you think knows better?

[Incentive]

Originally Posted by jongleur

My first thought was, "Wow, that's a lot of keel bolts."

36 of 'em.

LMHO

[hellosailor]

The nuts have "rust fusion welded" to the bolts and can't be separated with a wrench, so instead, you're going to break them free and then reduce the size of the keel bolts and install smaller nuts on them. Hmmm.

I'm not sure but that might actually be replacing something that is "solid" with something that is "shiny clean new and smaller".

I think I'd be tempted to stabilize them (seal them, pot them, treat them) and leave well enough alone.

[Tantalus]

Perhaps you could use a nut splitter

http://www.northerntool.com/shop/too...FQKhOgodiUAAJg

[73Islander36]

I have a 73 islander 36....my nuts are all in great condition despite the fact that they are rusty looking...

some bolt heads do have some damage...and had some chipping, but prodding the middle of said bolts revealed no further chipping and solid bolt...

I will be painting them and the bilges once I get it dry enough...

so if it aint broke no need to "fix" anything...

the reasoning behind this is that the nuts and washers are in good condition...and there is no evidence of water leaking up from the bolts etc...

I did however have a little repair work to the keel stub not the keel hull joint that needed some glass work...I also took the chance to rebed the joint with fast curing 5200

are all the nuts bad on this boat? if so and depending on year model,lead keel or iron it could help to simply sister in new bolts its apparently very hard to do if not impossible on the iron keels but on the lead keels you can

on my case I would be better off dropping the keel refairing the joints...and installing new bolts.

the issue with messing with the old nuts and bolts is you actually manage to do more harm and break bolts in the process...

you can weld more thread on and double up on nuts but I dont see where rethreading and making the size smaller is any improvement whatsoever

odd that other islander 36 owners recomended that...

[73Islander36]

if you do go this route make sure you are getting equal strength nuts and washers or stronger if going stainless...

[Found at Sea]

Greetings,
Thanks for your feedback re. my 1980 Islander 36 keel bolts. I have attached pix ( I think, not familiar with this sites process) for your examination. As you can see there are some nuts which are so corroded they are hard to distinguish. As a fellow I36 owner, how do you think they measure up? I would love nothing better than knowing that I only need to clean them up and seal them.
Many thanks,
Michael

[Terra Nova]

You must be the judge of what % of the original nut remains. But understand the non-linear relationship between that % and the % of strength lost. An uneven loss of mass of 20% of the nut could reduce the strength by perhaps 40% or more! Perhaps exceding whatever built-in safety factor the designer had allowed for.

Besides the reduction in the fastener's mass, the mechanical properties of the remaining "steel" have been compromised, possibly leaving them no longer fit for their intended purpose, whether you clean and paint them, or not.

Keel bolt deterioration is not a new problem. The new problem is that there are so many old boats that have, through never having been over-stressed, while never having been properly maintained, yet survived and accumulated in great number--this due to the attractively low purchase price. At this point in the boat's life, it is unlikely new owners will be prepared to do a proper repair, unless they DIY it. Even then, you really have to love it.

[73Islander36]

you have a deep bilge keel configuration...your also a late model...is your keel perhaps a shoal draft version?

im sorry to say...but your nuts are almost gone...also one bolt appears to be actually missiing a nut due to corrosion

the reason Im not messing with mine is the nuts and washers are still intact its that which give you the fastening strength and I do not have a keel hull joint separation or leak...

when careening the boat I verified this...

I would try to find out using a big magnet what your keel material is...if it is lead then I would sister in bolts...

there is a great pic on the islander36 association web site that shows this being done on a lead keel islander...he sistered in new bolts in a similar pattern to the old ones...

good luck

[73Islander36]

here is the link:

Adding Keel Bolts

notice his bolt nuts are in slightly better condition than yours

[Found at Sea]

Thanks for taking a look. Yes, they look pretty bad to me also. I think the keel is lead. I'm having the boat hauled next week so will have a chance to look closer. May need to put it on the dry for awhile for repairs. Thanks again.

[73Islander36]

I tried posting a link to the islander 36 website...but its waiting approval or something

if you haul out look at the keel hull joint...

when on the hard take some nuts off...

if the keel is lead sister in some new ones...

good luck

christian

[brantleychuck]

Did you buy the Islander 36. I have a IF36 with a nice. Beta 37.5 hp diesel. Needs a couple of things but NO keel bolt to worry over. 20 grand. Fort meyers beach Florida. I've owned her for. 8 years. Boat a bigger project boat, she needs a home. Chuck