did the heat damage my forestay and lifelines?

[RonRelyea]

Some of you may recall that last month, my boat (on the hard) was bow-to-bow with another boat that went up (or down???) in flames.

The heat from the other boat's fire melted a portion of my furler base and luff.

Would this heat compromise the integrity of the forestay or lifelines?

 

[Don S/V ILLusion]

Are these really answers you'd like us to guess about?

My guess is maybe...so replace them to be sure. Or you could have a qualified surveyor guess.

 

[rufus1138]

the furler drum is fiber reinforced plastic, its not exactly a weak or flimsy material. if it melted then your shrouds, under load, would be subjected to a performance envelope that i would not trust them in, metal behaves very differently as it heats, there are large ranges (dependent on the alloy) where the material is subject to increased elasticity. jet engines are limited only by this in how much power they can make, if you can get a turbine blade to hang together at a higher temperature threshold then you can increase the power output. your shrouds however were never designed with fire in mind, replace the forestay, associated chainplate, attaching hardware and terminal ends please.

 

[thinwater]

Perhaps we are being hasty, but it would be good to hear from a metalurgist. The conventional wisdom with 316ss is that short term exposures in ordinary atmospheres up to 1000F are ordinary and of no concern. The plastic would have not only melted but burst into flame. Aluminum would be melted or cracked. By temperatures of real concern, the aluminum would have melted.

http://www.atimetals.com/Documents/ati_316_tds_en.pdf

I've speced 316SS in furnaces in FAR worse conditions (higher temperatures with acid gases, exposed for many years), some of it under substancial load.

But I've never heated wire and then broke it. I'd bet my life that the weak spot on the lifelines is corrosion related and has nothing to do with this. I believe the same is true of the forestay; if it has been there for more than 10 years, the heat is not the major issue.

 

[Don Crowther]

Someone else will be paying for it not you why take the chance?

 

[Don S/V ILLusion]

Why take the chance regardless of who pays?

 

[Scott B]

I'm not sure how you could expect anyone on the intenet to give you a qualified opinion. Enough heat will damage them. We weren't there and we can't see the damage done. Hire a qualified surveyor to do a thorough investigation.

 

[Bill Roosa]

you guys are certainly a risk avers group. I'm with thinwater, If there was enough heat to damage the metal the fiberglass would have been set on fire. Since RonRelyea did not mention the boat catching on fire I'm thinking "it got hot" like when exposed to the sun. I've seen the sun make my SS shrouds to hot to touch.

 

[zeehag]

ask a rigger. they will know better than surveyor.

 

[Scott B]

you guys are certainly a risk avers group. I'm with thinwater, If there was enough heat to damage the metal the fiberglass would have been set on fire. Since RonRelyea did not mention the boat catching on fire I'm thinking "it got hot" like when exposed to the sun. I've seen the sun make my SS shrouds to hot to touch.

I agree Bill, it's unlikely damage was done, but with the very limited information given, no pics, no previous info, what is anyone possibly going to provide a qualified opinion on. I think maybe? perhaps? if your anchor didn't melt then you should be ok???

 

[thinwater]

Nylon rope parcially melted, lens partly melted, none of this fully melted....

450_600F for 10-20 minutes.

Melting points about 500 and 320F.

Just educated guessing. Obvious, I'm sure.

 

[Winkfish]

Jeez, guys! The OP asked a question. It could have easily been one of those things where everyone said "No problem don't worry" or everyone said "Definitely dmage, change it out." Instead, there's a difference of opinion. Don't jump down the guy's throat for asking.

 

[RonRelyea]

additional info

Thanks everyone for the input! It is all excellent food for thought.

Some things, as a neophyte, I maybe should have mentioned to start off wit but didn't think about until reading your replies ...

1) my boat is a Hunter Vision 32 ... it has an unstayed mast.... it doesn't rely on the forestay for stability. It is a fractional rig with a small 100% jib. The plastic luff of the furler was on fire for a few minutes - the bucket truck hit my boat first before the other boats in order to to keep the fire from spreading! Yes- I was there to see this since I live a couple hundred yards from the marina and got to the marina just as the fire trucks did!

2) The lifelines were the vinyl coated type ... the vinyl was barely melted for about 6 inches from the turnbuckle. I stripped off the vinyl and the stainless looks fine but ... ???? did the heat affect the swage????

That all being said ... there seems to be enough feedback from your posts to indicate the MAY be a structural integrity problem. That is NOT GOOD when dealing with lifelines and even though the mast wouldn't come down, a flailing jib/furler in a stiff breeze in the event of the forestay giving out could be dangerous too .... I think it's time to replace them.

Thanks again ALL!

 

[thinwater]

As a refinery equipment inspectore (part time) I like to know why I think what I think, not just say "replace it" everytime something gets dirty. For example, a gun is "unproven" when brand new, and at some point worn out, but reliability is actually at it's peak somewhere in the middle. Process vessels and big oil tanks are actually at greatest risk the first time they are used: was there a fabrication or design error?

One of the worst and provably least reliable gauges is how you "feel" about a piece of equipment, unless that feeling can be stated in quantitative terms. Gear can apear undamaged after a great strain; often the only way to evaluate the damage is to better understand the strain. Is a rope damaged when a climber falls? It depends on visible cutting and the impact force, which you can calculate. Heat in a refinery we go by what has melted, changes in patina and how is the paint.

In this case, since there is insurance coverage, I think the answer is obvious. I was only trying to introduce a way of looking at hidden damage. Just for your curiosity:

http://buildsmartercolorado.org/documents/Evaluating%20Fire%20Damage%20to%20Concrete%20Structures_tcm45-343618.pdf

 

[Benny17441]

The forestay is made of stainless steel; a little heat is not going to damage it. Now if the furler drum is being replaced it follows that the extrusions may be removed and the wire exposed; it would make sense if the boat is older than 20 years to replace it at this time. It is one of those things that mechanics say "as long as I'm here it would be cheaper to replace it now". As far as the lifelines if the plastic cover got scorched just replace those sections that were damaged.

 

[Brian S]

Replace the lifelines for other reasons.

From what I've been reading, you should replace the lifelines - not because of heat damage or melted vinyl, but because coated lifelines are bad news. Stainless steel requires oxygen to form a protective layer of oxide and thus prevent steel oxide forming (rust.) (Sorry, but I forget which of the components of the SS alloy provides the protective oxide. ThinWater probably knows. ) Anyway, when you put SS in an oxygen free environment, it then becomes subject to rust. Which kinda doesn't make sense, what with the rust being an oxide, but this is proven. So, anyway, coating SS wire with vinyl makes rust under the vinyl more likely, and you won't know the strength is compromised until the rust expands and splits the vinyl. Also, most standing rigging fails at the swages, because there is limited oxygen getting in where the wire is crimped. We should always pay close attention to cracking or staining at the swages of our standing rigging.

Usually, you can step up a size in your lifeline wire moving from coated to uncoated, in order to fit holes in stanchions, etc. Or, you could replace your wire lifelines with Dyneema single braids. I think it's CS Johnson making some very nice looking termination fittings for fiber lifelines.

Personally, I have 2 lifelines on my boat which aren't quite good for "life" lines. (They are low, and kinda knee-cappers.) I do like them as backrests for windy days, sitting on the coaming tops, but that's because my little boat sails slightly more like a dinghy than a big keel boat. Next season, I think I'll replace mine with bigger wire that I cut and crimp myself.

 

[BobM]

Given the likely age of your boat they likely are due for replacement anyway (1989-1992 For the V32?) if they haven't been already. They are far more likely to be corroded due to being vinyl coated than fire damaged.