Maybe not enough hardner??? What should I do?

[loges17]

Hi there

Bit of a novice in this boat restoration caper...been going at it now for 2 months (only have weekends to work on the boat so it has been a slow process to due bad weather). I have been using this forum to research everything I have been doing and it has been great...although over the weekend took some advice from a guy I thought knew what he was on about and I think I have come unstuck now...ok too the point...

I began poly glassing in a new deck with strand mat (supposedly marine ply...but I am bit skeptical...seems too soft...) when the guy I got advice from told me to use less hardener than what was required on the instructions (said it would give me more time to work with it) but now the section that I did with that mixture hasn't hardened and I want to know what I can do about it...I have tried looking up options on the forum but it has been difficult to find specific information on it. From the tidbits I have seen it seems I have to scrape it up and clean it the area and start again. Is this true? Is there any other suggestions...even though its been a couple of days in cold weather will getting some heaters in there make any difference? or if I poly resin over the top with extra hardener will it seep in and harden the other un-dried portion at the same time?

The other problem I am faced with is that I did another batch on a different section which has hardened...these two sections overlap so if I scrape off up to the dried part must I sand down the overlapped section incase the bond isn't strong?

Cheers for any suggestions - Loges

 

[bear_69cuda]

Re: Maybe not enough hardner??? What should I do?

I think with some additional time and heat ( halogen light close to surface ) it should cure...

 

[Jeff Walkowiak]

Re: Maybe not enough hardner??? What should I do?

I believe he hit it on the head,, you need heat to get it to kick ,try a small area with a heat gun or a hair dryer and see if it works on that spot,, if it does you know what you need to do.

 

[Bob_VT]

Re: Maybe not enough hardner??? What should I do?

The majority of the novice mistakes are not properly mixing the resin (not stirring it enough) and tryinf to apply the resin when the temperature is too cold.

Applyinf more over the top may not do it

 

[humdinga fisherman]

Re: Maybe not enough hardner??? What should I do?

perhaps you should have listened to the other person helping you that day that said more hardener was required....

I think you'll have to get your hairdryer out and see if that works...

 

[92excel]

Re: Maybe not enough hardner??? What should I do?

if you dont have the ability to heat the entire garage then you can put old tarp or blankets over the boat and only heat the temporary enclosure with a halogen light or electric space heater. you can get it nice and toasty! just be careful not to put your heat source too close to anything.

 

[seaman campbell]

Re: Maybe not enough hardner??? What should I do?

Heat and more heat, it will harden.

TC

 

[loges17]

Re: Maybe not enough hardner??? What should I do?

ok I have had a quick go at it with a heat gun and i think it seems to work, my only question is when heating it up do I just need to get it hot for a short time and then let it cool and as it cools it cures...Just wondering how long am I suppose to have the heat source in the one area before I move it...or am I suppose to have the whole area heated up for an extended period? It seemed the hotter it got the gooier it became...

 

[danond]

Re: Maybe not enough hardner??? What should I do?

You don't need to light it on fire. Get it over 70 degrees and you're fine. Do that for as long as you can; 5-6 hours at that temp, at least.

 

[waterwezl]

Re: Maybe not enough hardner??? What should I do?

Listen to 'em brother. I did the same thing while putting in stringers. I covered the boat with a tarp and left 2 halogen lights in it overnight and all day while I was at work. That evening I came home to dry poly. I, like you, thought I was gonna have to scrape it all up and start over. But it hardened fine and I was able to sand on it that same night. Patience and heat, it'll harden. :redface:

 

[oops!]

Re: Maybe not enough hardner??? What should I do?

well.....sorry to say.....this thread is way off the rails.....

bob vt said it.

now.....just because the resin hardens....it doesnt mean the resin is doing what the manufacturers intended it to do....thats why the manufactures instructions were on the can.

be it well known......poly resin is a great material.....it can seem to do anything as long as it gets hard..!....but that is not the case in boat building....i know speaker box builders go way out side the specs of poly resin....and it works for them......but they do not need the makium stregnth or stiffness that we boat builders need from poly.
we are using the maximum stregnth that poly affords......in fact....some home builders choose to go stronger with ve resins....or stronger yet with epoxy.....

to use a resin that is not properly cured is asking for failure.
cure it....and grind it all off !....get rid of it and do it correctly, or you will experiance failure.

to "hot coat" it.....is asking for failure also.....the resin will cure....but the top will be brittle with the added heat from over catylising....and the under coat will be soft......resulting in a irregular bond.

so...... really.....grind it off and re do it.

sorry for the bad news.......but thats the facts.....

cheers
oops

 

[J. Mark]

Re: Maybe not enough hardner??? What should I do?

I love my epoxy

 

[ondarvr]

Re: Maybe not enough hardner??? What should I do?

Incorrectly mixed epoxy is no different, the lesson just costs more.

 

[J. Mark]

Re: Maybe not enough hardner??? What should I do?

yes, I agree, but 1-1 ratios are a bit harder to mess up.

 

[Mark_VTfisherman]

Re: Maybe not enough hardner??? What should I do?

What oops! said is right.

Sometimes I have added a drop or two extra of hardener for top coats which I might add as a last step before paint, and I have bailed myself out of soft cures too. But because of the way the catalyst acts, I would agree with oops! again and say not enough hardener is a bad thing.

I have used a 1500 watt electric fan-forced heater under a tarp to raise temps to 75+ before and cured off slow-drying (due to low temp) epoxy and polyester. But more heat does not compensate for not enough chemical reaction, which is what you get with not enough hardener.

 

[CATransplant]

Re: Maybe not enough hardner??? What should I do?

I guess the lesson here is that the folks who wrote the instructions on the container might just know more than the random guy down the street. I've gotten lots of bad advice from well-meaning people. I just ignore them all and read the instructions carefully and follow them religiously. I've never had a problem doing it that way.

 

[loges17]

Re: Maybe not enough hardner??? What should I do?

Thanks for everyones comments, I have taken it all on board. I let you know how things turn out...