resin curing time...

[hotmerc]

i am currently in the process of repairing a "strake" or rib" on the hull of my 27 ft 1988 carver santego. the rib developed stress cracks from some air pockets that got in the rib some how. i ground down about a 5ft section of the rib and had a piece of wood fabricated to replace the 5ft section. prepared the resin epoxy mix, got the glass wet with it, wraped the wood rib in the wet fiberglass cloth, rolled out the air and stuck it in place bracing it up with wood. now its been 2 days since i did this. how long does it take for the resin to cure before i can take the braces off to layer some more on? as of yesterday it was still tacky...

thanks

 

[fuzzeywiggler]

Re: resin curing time...

It should be dry by now... What temp are you doing this at? I would recommend scuffing up the area again and checking for bubbles before the next layer.

Is the leftover resin you used dry? Are the brushes ? Or are they still tacky too?. If they are there might be to much moisture in the wood...just a thought. Someone should now the reason.

Fuzzey

 

[hotmerc]

Re: resin curing time...

temps were in the mid 60's. soon after we finished it began to rain. don't know it that has an effect on it, i'm sure it might. i haven't checked it today but will tomorrow. as of yestarday the left over was "pudding" like thinkness.

 

[fuzzeywiggler]

Re: resin curing time...

Was the area uncovered in the rain? That cand't be good. I only put on resin on a min of 15 celsius (60degF) and a max of 25 of 75 ish has the temp dropped below 60 the past few days? I wonder If you could rub a little amount of harderner on? or if that would just mess it up even worse...

Fuzzey

 

[SgtMaj]

Re: resin curing time...

Curing time depends on how much hardener used as well as temp... and can also be influenced if not mixed with the hardener well. Typically it should be cured in a day and completely dry after 2 days... though I prefer mixing in even more hardener so it only takes a few hours to dry.

 

[i386]

Re: resin curing time...

If you didn't mix it right, it won't ever cure. Epoxy has to be mixed in a specific ratio. The 2 parts combine in a chemical reaction to form a new compound. If the ratio is off, the reaction either never happens or happens incompletely.

It works a little differently than polyester resin (where the resin will eventually harden on it's on and the catalyst just gets things going). You can't vary the amount of hardener in epoxy to adjust cure time.

Polyester -> Resin and catalyst (cure time adjusted by adding more catalyst) * to a point
Epoxy -> Resin and Hardner (cure time adjusted by using a faster hardener) * accurate mixing is critical


I'd pull it off, clean it up, and start over (don't ask how I know:redface.

Just my $.02.

 

[SgtMaj]

Re: resin curing time...

I386 is right... to a point... though the amt of hardener added to epoxy can be varied slightly, but too little and it'll never cure, too much and you'll get the same thing, though it's generally more difficult to mix too much hardener in I've found.

PS - I mostly work with polyester resin, and the few times I have messed with epoxy, well let's just say that the first time turned out similar to your predicament.

 

[Coors]

Re: resin curing time...

If you didn't mix it right, it won't ever cure. Epoxy has to be mixed in a specific ratio. The 2 parts combine in a chemical reaction to form a new compound. If the ratio is off, the reaction either never happens or happens incompletely.

It works a little differently than polyester resin (where the resin will eventually harden on it's on and the catalyst just gets things going). You can't vary the amount of hardener in epoxy to adjust cure time.

Polyester -> Resin and catalyst (cure time adjusted by adding more catalyst) * to a point
Epoxy -> Resin and Hardner (cure time adjusted by using a faster hardener) * accurate mixing is critical


I'd pull it off, clean it up, and start over (don't ask how I know:redface.

Just my $.02.

If not mixed right, the quote is correct.

 

[salty87]

Re: resin curing time...

yep, 'experimenting'...learning on the real deal is expensive and timely. been there, etc...

also, epoxy isn't my thing so someone correct me...shouldn't the layers be done when wet so they chemically bond as well?

 

[i386]

Re: resin curing time...

shouldn't the layers be done when wet so they chemically bond as well?

Someone correct me if I'm wrong, but I think that is true with epoxy and poly.

 

[oops!]

Re: resin curing time...

rip it off and re do it......

sorry, but either you didnt add enough hardner, or you didnt mix it well enough.

the repair will not work. it will fail.......

the manufacturers directions need to be followed exactally.......im not certain of the epoxy mix ratios.

as far as mixing......swishing it with a stick...is not really good enough.
you really gotta mix it well, scraping the sides of the bucket, and the bottom and really mixing it well....anything less is an improper cure, and a poor bond.....

when done properly.......
that epoxy will grab whatever you want and hold so hard, youll wear out a grinder disc trying to get it off.