!! MEKP SCREWUP !!

alheim

Cadet
Joined
Jun 3, 2006
Messages
11
I'm not generally this dumb, but today my friend and I were installing the last stringer in our restoration project (we haven't done any work on the boat since the summer), and while I mixed up some peanut butter, I completely screwed up the mix ratios:

Instead of using 1/100 MEKP/Resin, I used about 1/1000. I don't know what I was thinking, but instead of using one milliliter per hundred milliliters of resin, I was using one drop.

We didn't realize my mistake until we had peanut-buttered in the whole stringer .. literally sitting there for half an hour until we realized it wasn't hardening at all, and then realized what happened.

The last thing I want to do is to take out the stringer and redo it. My idea was to spray the peanut butter w/ MEKP (carefully, of course). I'm sure that will make it set just fine, at least on the outside, but will it work its way in to the deeper parts of the fillet?

Thanks for your help - and hurry! It's going to rain any minute!

-Alheim

p.s. - my friend is currently subduing his rage with a cigarette, haha
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: !! MEKP SCREWUP !!

let us know what happens if you can. good question.
 

iwombat

Captain
Joined
Jul 12, 2006
Messages
3,767
Re: !! MEKP SCREWUP !!

I think you'll probably be better off mixing up another batch properly and putting a light coat over the whole thing. MEKP is a catalyst to trigger a reaction in the resin, it's not a hardener for a two-part system. Another layer of properly mixed resin will kick off the unmixed stuff underneath.
 

Plainsman

Rear Admiral
Joined
Apr 2, 2006
Messages
4,062
Re: !! MEKP SCREWUP !!

iwombat said:
I think you'll probably be better off mixing up another batch properly and putting a light coat over the whole thing. MEKP is a catalyst to trigger a reaction in the resin, it's not a hardener for a two-part system. Another layer of properly mixed resin will kick off the unmixed stuff underneath.

What does "kick off" mean?
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: !! MEKP SCREWUP !!

erm...

1. 1% MEKP to resin is not the correct ratio
2. How much mud are you mixing at a time ?
3. you CANNOT spray MEKP on top of your mud

sorry to say..you have to extract ALL and start over for proper crosslinking in your resin.

once again..how much are you mixing at a time ?
 

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: !! MEKP SCREWUP !!

I know this is not helpful but I could not resist. I have a seething detestation for polyester resin!

I would also say that you have to clean the bulk of it out and start over.
 

iwombat

Captain
Joined
Jul 12, 2006
Messages
3,767
Re: !! MEKP SCREWUP !!

On second thought, the other fellas are correct - remove it. Especially since we're talking about stringers here. It just HAS to be right.
 

alheim

Cadet
Joined
Jun 3, 2006
Messages
11
Re: !! MEKP SCREWUP !!

Yacht said:
erm...

1. 1% MEKP to resin is not the correct ratio
2. How much mud are you mixing at a time ?
3. you CANNOT spray MEKP on top of your mud

sorry to say..you have to extract ALL and start over for proper crosslinking in your resin.

once again..how much are you mixing at a time ?

Then what is the right ratio? According to http://www.uscomposites.com/pdf/MEKPDirections.pdf - it's one oz per gallon, which is actually a little less than 1%.

We're mixing at most about half a gallon at a time, with both of us working with it together.

I guess we might re-do it. Thanks for your advice - anyone else?
 

OhioLowell

Petty Officer 2nd Class
Joined
Oct 21, 2005
Messages
189
Re: !! MEKP SCREWUP !!

Has is hardened out yet?

Just curious, I'm sorry I have no other advise as I'm pretty new to this stuff.

Lowell
 

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: !! MEKP SCREWUP !!

it needs 4 drops per ounce, and will kick in 20 min at 70 degrees
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: !! MEKP SCREWUP !!

erm..It wasnt my fault..I was just trying to help..

your link is incorrect m8..

YD
 

plinko

Recruit
Joined
Apr 28, 2007
Messages
3
Re: !! MEKP SCREWUP !!

1.5 percent mix ratio, 1 kg of resin you will need 15 cc mek cataylst.Anyone using polyester resin should invest in a set of scales and the proper squeeze bottle for their cataylst, they are only a few dollars and will give you the proper mix everytime. Some people think using more cataylst to speed up a job is good, but in fact is not. Too much will create heat, make a brittle lamanition, the same goes for too much resin.
 

flashback

Captain
Joined
Jun 28, 2002
Messages
3,987
Re: !! MEKP SCREWUP !!

Just went and looked a my gal of resin and it says to mix anywhere between 9 and 17 cc per quart depending on what the temp is in the work area...as for what you already did, like the yacht doc says, you will need to remove, it will not ever harden properly....
 
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