Heat & Fiberglass...

[Seafire327]

Now, I know that they don't combine well at all, but there have been a few posts lately about keel bolts, and it got me thinking about mine. I've been trying to figure out a way to caress the steel bolts out of my cast iron keel for some time. After reading some tactics on automotive blogs, and working on my own, I know that heating a bolt that is stuck, is a good way to get it moving. I was wondering weather I could get a piece of plate steel with a 1/2" hole cut out and use it shield the bilge while I carefully (CAREFULLY!!!) heat the bolt with a torch. A few heatings and coolings should free the bolt and not have me worry about snapping the bolt in the keel... I guess I'm worried about heat transfer to the glass, etc.

Thoughts? I appreciate any input

[mitiempo]

If you have a Columbia 26 MKII as indicated in your post, you have a lead keel. The bolts in a lead keel will not turn as the section of the bolt in the keel is "J" shaped. The keel can be removed by undoing the nuts on the bolts in the keel stub portion of the bilge.
Columbia 26 Mk II and K Specifications

[Seafire327]

Yea, I'm not sure why the spec sheet on that site says lead, but it is definitely cast iron. I've ground it down and faired it a few times. Here is the tech drawing that I meant to attach to the initial post to better illustrate what I mean.

[mitiempo]

I guess the info on that site is incorrect. I guess if the threaded section has been moist at all it has corroded in place over the years.
You will have to heat the bolt throughout its length, and the keel will resist that as it is cool - or cold this time of the year.
Are you dropping the keel or just trying to pull a bolt for inspection?

[Seafire327]

I'd like to inspect, and replace if necessary, one at a time. I'm fairly certain that the bolts have been replaced before, but they are showing some age and I think a check sooner than later is in order.

[mitiempo]

Are they steel or stainless steel?

[Seafire327]

Zinc coated steel. Last year I removed the nut off the foremost bolt, and and replaced it with new, partially to see if the bolt would withstand the re-torquing. No problems there. So I think I'm in fairly good shape, but I'd like to know for sure. Also thought of using penetrating oil over the course of a few weeks, but again, I don't know if that might have an adverse effect on the surrounding hull structure.

[mitiempo]

I don't think penetrating oil will harm the hull, but I am not an expert. The best to use is PB Blaster - it works better than any other. But I don't know how far it will penetrate along the bolt threads if they is corroded in place.

Perhaps someone else will post an answer.

[Seafire327]

I know PB is the best, but it also eats styrofoam on contact...Which was my worry. Thanks for the input!

[sailingdog]

I would try penetrating oil instead of heat... PB Blaster works wonders.