Is it possible to bond battens to fibreglass roof in these temps?

[steve yates]

or is it too cold? I'm wondering if itys a bit like painting, where the temp needs to be reasonable to start the work? Or does it just take longer to go off the colder it is?

 

[pvb]

I wouldn't try it right now; there are condensation issues as well as low temperature.

 

[MystyBlue2]

I would recommend that you leave it until spring unless its an emergency!

I fibreglassed some gussets from boat deck to transom in late October with poly resin and 4% catalyst. Outside ambient temp was 8°C and took 2 days to fully cure and thats with me keeping it warm with the missus hairdryer. Then the flowcoat on top was a nightmare to cure too.

I would be concerned about it never fully curing and leaving a perminent tacky mess that would require more work and money to rectify in these current temperatures.

If theres a possibility to put it off then i would personally.

If not, Use more catalyst percentage to resin (should be a table on the bottle) and keep the chill and frost off and warm with a heater or a hairdryer (keep it at a distance from work peice).

Usually as standard procedure anything 5°C and under should be avoided.

Dont use a heat gun as it will overheat the resin and cause it to crack.

I may stand corrected but hope this helps.

 

[SvenH]

I have to guess battens are always wood?
I'd never use polyester to bond wood, as polyester does not "bond" wood.

I'd always use epoxy, especially for older fiberglass.
If too cold you can use a variant suitable for colder environments, that is often the quick variant for normal temperatures..

If the area is not too big, you can also try using an halogen light to radiate warmth to the surface.
I tried this once when freezing to use normal 15 degree epoxy.
Lamp was too close, epoxy got too hot...

 

[Aurai]

Have a look at spec sheets for your chosen product. Jotun, epoxy primer was fine at 11 degrees and plenty of Jan - March days reach 11. We did use low temp additive to help us start earlier when temp was 8 degrees and rising! You c not work very late doe the condensation issue mentioned.

 

[Keith 66]

You do not say what you are thinking of bonding with? If epoxy its too cold & it wont cure unless you have a good heater Infra red is good as it heats the surface not the air.
If polyester simply adding more catalyst wont work either as there is a limit as to how much you can add.
However if you add Cobalt accelerator to the resin & mix it in well before adding the catalyst you can make polyester work well down to zero degrees or below. Cobalt accelerator is not stuff to mess with if you dont know what you are doing as if it comes into direct contact with peroxide catalyst a violent reaction that can be explosive results! This is why virtually all resin comes pre accelerated today. Fibreglass roofers often boost resin with cobalt in winter.

 

[atol]

if you need to get battons in place you can use an expanded polyeurathane glue ,the damper the better! Gorilla Glue 250ml
Then fillet and glass over when the weather gets a bit warmer.
west system with a fast hardner should be okay down to about 8 degC

 

[PaulRainbow]

I have to guess battens are always wood?
I'd never use polyester to bond wood, as polyester does not "bond" wood.

Good heavens, i'm deeply in the sheet then, as is almost every other GRP boat owner in the galaxy, my bulkheads, floors etc, etc, etc are all bonded in with polyester.

 

[MystyBlue2]

Good heavens, i'm deeply in the sheet then, as is almost every other GRP boat owner in the galaxy, by bulkheads, floors etc, etc, etc are all bonded in with polyester.

Yeah i was starting to worry as all the jobs ive done have been ply and poly...with good preparation i assumed it would be fine.

All seems solid so far and no delamination as of yet.

 

[steve yates]

Thanks all, very useful.
Kieth, I'll pass on the cobalt stuff, I'd just blow up the boat
I'll prob go with atols suggestion of gorilla glue instead. Doesn't need glossing over, I'm just screwing some hardboard panels onto it.

 

[atol]

Thanks all, very useful.
Kieth, I'll pass on the cobalt stuff, I'd just blow up the boat
I'll prob go with atols suggestion of gorilla glue instead. Doesn't need glossing over, I'm just screwing some hardboard panels onto it.

There are cheaper alternatives to gorilla glue as well if you buy from CFS fiberglass online or look around.
good idea to abrade the surface you are bonding to as well.
Any excess glue can be easily cleaned off hard surfaces after it has cured with a chisel and sand paper
wear gloves as hard to get off your hands and protect any areas that need it from drips

 

[dankilb]

Know I’m like a broken record when it comes to PU adhesives on here - but why not simply use a builders polyurethane adhesive in a tube? Cures through humidity anyway and cold only slows it slightly. Costs a fiver for 300ml. Can he had around the corner (toolstationt/screwfix). And comes off with a scraper and maybe a bit of heat if it ever needs to (and over the life of a boat, it probably will).

 

[Keith 66]

^^^^^ This, PU sealant, doesnt have to be Sikaflex as thats just an expensive version. Will stick like the proverbial & its moisture curing so will go off whatever the weather. As for foaming PU glues, Gorrilla glue is a masterpiece of marketing, you can buy far cheaper equivalents that work just as poorly!

 

[alahol2]

^^^^^I've recently bonded some backing pads with OB1 from Screwfix. They're not going anywhere (even without the bolts going through).

 

[dankilb]

To add... many of us probably would use (thickened) epoxy for this in warmer weather. For me, mainly just because there’s always some on hand, so I use it for almost everything.

But it’s just not worth fighting with the ambient conditions when it’s too cold - unless the work is structural and absolutely cannot wait (in which case I’ve also had good experiences with laying up epoxy/glass over winter with the help of heaters). It’s stressful leaving a load of glass curing with heaters overnight though - lots could go wrong (either a wet mess or a burned boat in the morning!)

 

[fisherman]

I would recommend that you leave it until spring unless its an emergency!

I fibreglassed some gussets from boat deck to transom in late October with poly resin and 40% catalyst. Outside ambient temp was 8°C and took 2 days to fully cure and thats with me keeping it warm with the missus hairdryer. Then the flowcoat on top was a nightmare to cure too.

40%? Are you sure? Max 2% in my book.
A chap here who spent his life making mouldings had a chart of ambient temp on the wall. He adjusted the accelerator, not the catalyst. As above do not mix neat accelerant and catalyst.

 

[MystyBlue2]

40%? Are you sure? Max 2% in my book.
A chap here who spent his life making mouldings had a chart of ambient temp on the wall. He adjusted the accelerator, not the catalyst. As above do not mix neat accelerant and catalyst.

Yes i do apologise i meant to say 4%!!!

Thank you for pointing that out i will amend my above statement.

Also for my projects i used East coast fibreglass supllies used poly resin with MekP catalyst as thats all thats needed to for chemical reaction to be achieved. I did not need to use and additional accelerators.

 

[Kilo]

if you need to get battons in place you can use an expanded polyeurathane glue ,the damper the better! Gorilla Glue 250ml
Then fillet and glass over when the weather gets a bit warmer.
west system with a fast hardner should be okay down to about 8 degC

Hey there, is this through direct experience? I've wondered & decided against pu adhesive bonding wood to fiber glass. I suppose if the fg is v rough it might fill small rugosities and so adhere that way? Be really interested to know how it goes, you can be the avalanche poodle Steve

 

[[178529]]

Know I’m like a broken record when it comes to PU adhesives on here - but why not simply use a builders polyurethane adhesive in a tube? Cures through humidity anyway and cold only slows it slightly. Costs a fiver for 300ml. Can he had around the corner (toolstationt/screwfix). And comes off with a scraper and maybe a bit of heat if it ever needs to (and over the life of a boat, it probably will).

I built a track orientated car, a Dax Rush where the front mudgaurds are bonded to steel rails with PU. I was a bit dubious as they take a lot of strain but ther bond is probably stronger than the grp.

 

[atol]

Hey there, is this through direct experience? I've wondered & decided against pu adhesive bonding wood to fiber glass. I suppose if the fg is v rough it might fill small rugosities and so adhere that way? Be really interested to know how it goes, you can be the avalanche poodle Steve

used it for the initial fit for all the batons,pads and bulkheads on my catamaran before filleting and glassing in with epoxy, you do need to remove wax before and after sanding FG ,but sticks as good as PU paint,and as a gap filler it avoids hard spots on the hull from bulkheads