Cold temperatures and vinyl-ester resin

[GILow]

One for the resin-heads out there.

I am ready to build my diesel keel tank. For many reasons, I have elected to go with vinyl-ester.

The plan is (or was) to line the existing keel void with a layer or two of CSM and vinyl-ester before putting a pre-fabricated vinyl-ester lid on the whole thing and bonding that lid to the hull with vinyl-ester or perhaps epoxy.

But I am having some temperature problems.

Current daytime temperatures are around 15 degrees Celsius (60 degrees Fahrenheit). I have been warming my construction room to 22 degrees C, (71 F) and things have been working well making a stand alone tank for another job. But I was a bit careless with my temperature control two days ago and had a batch fail to cure. (messy).

Now I am ready to move down to the boat and do the keel, and I realise I have a problem. I can get the interior of the boat warm enough, but the keel is in the water. Current water temperature is 14 C (57 F).

Will it be enough to have the resin mix nice and warm before I apply it, or do I have a problem?

Matt

[coopec43]

I would never build a fuel tank integral with the hull!

[coopec43]

https://www.boatdesign.net/threads/f...l-tanks.41387/


Fiberglass Fuel Tanks - Avoid At All Costs?
https://www.thehulltruth.com/boating...l-costs-2.html

[Wind River]

I finished laying 500 lbs of vinyl ester resin on my decks. I intentionally laid the glass at temps below 60 degrees to extend the working time. Several times it was in the low 50's. As soon as it warms up it will cure if it is catalyzed at 2% by weight. If needed ad a heat lamp to get it up above about 65 degrees and it will kick off.
I was concerned at the beginning but a call to the resin manufacturer and I was assured that in this application I would be fine.
By the way, I have fiberglass diesel tanks in my 1982 Hudson Force 50 with no problems at this point.

[Uncle Bob]

Matt, given the extreme thickness of you'r hull, especially in the keel/bilge area I can't see any flex happening so the integral tank I believe will be fine. As to temp, I would go with the heating of the cabin to the desired temp for at least a day prior and then glass away. The heating of the cabin will make the resin cure as required and the day of heating will ensure that the hull is as warm as is possible.
By the way I have two large fibreglass tanks that hold around a thousand litres of diesel, if I filled them. No problem to date.

[GILow]

Originally Posted by Wind River

I finished laying 500 lbs of vinyl ester resin on my decks. I intentionally laid the glass at temps below 60 degrees to extend the working time. Several times it was in the low 50's. As soon as it warms up it will cure if it is catalyzed at 2% by weight. If needed ad a heat lamp to get it up above about 65 degrees and it will kick off.
I was concerned at the beginning but a call to the resin manufacturer and I was assured that in this application I would be fine.
By the way, I have fiberglass diesel tanks in my 1982 Hudson Force 50 with no problems at this point.

Thank you, that's very reassuring (the temperature bit.) I did not know I could restart the reaction by warming the tank, darn, I cleaned out all the uncured stuff and tried again, maybe I should have just warmed it up?


As for the whole suitability thing... I ignore the panic-police. There's nothing at all wrong with fibreglass tanks for diesel. If the poster had looked PROPERLY at the hysteria laden links they supplied they would have noticed that the problems are mainly appearing with the addition of ethanol to PETROL, and it that IS proving to be a problem. The motorcycle guys are all going crazy.

Old boats like ours have had diesel tanks in the keel since dinosaurs walked the earth without any problems. Of course, one day they may add something to diesel that causes problems, but until then I will sleep well. And if they do, I guess I will have to cough up some big $$$ for custom tanks.

[GILow]

Originally Posted by Uncle Bob

Matt, given the extreme thickness of you'r hull, especially in the keel/bilge area I can't see any flex happening so the integral tank I believe will be fine. As to temp, I would go with the heating of the cabin to the desired temp for at least a day prior and then glass away. The heating of the cabin will make the resin cure as required and the day of heating will ensure that the hull is as warm as is possible.

Thanks UB, yeah, like you, I wasn't worried about the practicality of the idea, researched this to death over a long time. And no, flex in an old Swanson is not something I think I have to worry about.

I like your idea of long term heating, not least because I am on a fixed rate for my power at the marina.

[coopec43]

Originally Posted by GILow

Old boats like ours have had diesel tanks in the keel since dinosaurs walked the earth without any problems. Of course, one day they may add something to diesel that causes problems, but until then I will sleep well. And if they do, I guess I will have to cough up some big $$$ for custom tanks.

Maybe I have read too many articles like this
Leaking fiberglass fuel tank
https://www.sailnet.com/forums/gear-...fuel-tank.html


Apparently polyester resin was a much better quality on older boats than the resin used in modern boats.

[GILow]

Originally Posted by coopec43

Maybe I have read too many articles like this
Leaking fiberglass fuel tank
https://www.sailnet.com/forums/gear-...fuel-tank.html


Apparently polyester resin was a much better quality on older boats than the resin used in modern boats.

OK, seriously, I wasn't going to bother responding, but I am getting tired of this.

One of the key aspects of RESEARCH is MEANINGFUL data.

You just linked a post where someone said "My fiberglass fuel tank leaks". Aside from saying the tank is 15 gallons, there is no data on the tank. They don't even say which fuel they are using. They don't say if the tank is freestanding or encapsulated. They don't say ANYTHING of relevance. They don't say what sort of boat they have. Oh, and one of the more reasoned responses actually linked to an article explaining how to make a fibreglass tank.

You say "Maybe I have read too many articles like this", but clearly, you have not actually read the article.


The previous links you gave were to people having problems with PETROL in their tanks. So far, you have linked nothing but irrelevant rubbish in your desperation to tell me what I am doing wrong.

And I honestly don't know why.

You also went to some trouble a while back to tell me I don't know what my boat weighs, which, frankly, was just plain weird. (Oh, and you were wrong, but I shouldn't really have to spell that out.)

Then you PM me to tell me I should ask some guy about electrics, which was kinda nice of you except that he's a friend, and I don't really know why you were telling me that I needed electrical help.

I asked for help with resin cure temperatures. Not for a bunch of uninformed irrelevant nonsense from google.

So, please, give me a break.

[coopec43]

GILow

I'm really sorry I have upset you. (I hope your day improves)

Clive

[GILow]

Originally Posted by coopec43

GILow

I'm really sorry I have upset you. (I hope your day improves)

Clive

It just got better.

[Wind River]

Originally Posted by GILow

Thank you, that's very reassuring (the temperature bit.) I did not know I could restart the reaction by warming the tank, darn, I cleaned out all the uncured stuff and tried again, maybe I should have just warmed it up?


As for the whole suitability thing... I ignore the panic-police. There's nothing at all wrong with fibreglass tanks for diesel. If the poster had looked PROPERLY at the hysteria laden links they supplied they would have noticed that the problems are mainly appearing with the addition of ethanol to PETROL, and it that IS proving to be a problem. The motorcycle guys are all going crazy.

Old boats like ours have had diesel tanks in the keel since dinosaurs walked the earth without any problems. Of course, one day they may add something to diesel that causes problems, but until then I will sleep well. And if they do, I guess I will have to cough up some big $$$ for custom tanks.

My first run in with the resin not curing even after 12 hours of below 60 degrees had me pretty concerned. While I was deciding what to do the sun came out the next morning, my enclosure warmed up and, BOOM! It kicked off like I just laid it in 70 degree temps.

The manufacturers rep told me the resin must have heat to catalyze. The only drawback to what I was doing was that the resin would not be quite as hard. He also said that a post cure of about 150 degrees would bring it to almost full hardness. If recall correctly, I catalyzed at about 1.75% by weight to slow it even more. (I meant to say catalyze at "not more" than 2% in my last post)

You must be sure of the amount of catalyst though. No guessing, use a scale.

[Wotname]

Get a UV light on to it - that will speed it up big time - at least it does for poly and epoxy so I am assuming vinyl will be the same.

By the way, what the manufacturer say about max catalyst ratio and temperatures???

[Wotname]

Originally Posted by Wind River

.........

You must be sure of the amount of catalyst though. No guessing, use a scale.

This is excellent advice. While epoxy must be measured, poly should be measured especially if you want repeatable results.

Again I'm assuming vinyl will be similar - but I do know that measured qualities will never hurt!

[GILow]

Thanks guys. I am being (unusually for me) careful with this job. My supplier specified 2% by weight, so by weight it is.

Of course, my maths may be a bit erratic thanks to the fumes, but I THINK i am getting the numbers right. The problem is, each time I have to put the pot on the scales to zero it. Then, remove the pot from the scales, decant from the 20kg tin into the pot, return the pot to the scales before they reset, THEN do the maths to calculate 2%, add that to the number on the scale and pour in the catalyst from the small bottle.

All this gets a bit hard when the fumes get me.


But aside from my one failed cold batch, it has all been going well.

So well, in fact, that I am starting to plan the ice-box build. That can be fabricated here at home like the heater tank.

However, the keel fuel tank, two water tanks and the black and grey water tanks will all have to be built in-situ. Hence my concerns about temperatures.