Amine blush- am I screwed?

Hi, I'm currently replacing a stringer in my 23' power boat along with a bulk head and a small interior sole. I just got back from putting the 1st layer of glass over the stringer (bedded the stringer previous to this) with West System epoxy. I read extensively (relative to the project and I should mention that I am new at this) and I recalled that amine blush can occur for various reasons. I remembered that it needed to be removed- so I wiped it away with paper towels then wiped again with an acetone soaked cloth. Opps!- When returned home and I re-read my literature the proper method was to use water, dry and sand. Have I totally ruined my work? Any subsequent layers epoxy/glass will be subject to the bottom layers bond or lack off. There was quite a bit of blush before I wiped everything done and it seemed like it was gone afterwards but I'm a bit worried that I just screwed up this repair.

Thanks in advance for your replies,

Alan

 

You should be fine. Maybe do a light sanding next time instead.

 

Thanks! When I went back this eve the bond seemed good. But it's fresh down and not under stress. I do tend to push the boat a bit. Lake Ontario can kick it up at times. That's when i want the bonds working!
Thanks again,

Alan

 

West recommends that you wash the area with water and scotch brite pads and then to wipe up the residue before it dries. Sanding will not do a good job of removing the Amine blush. Only after it is all removed should you sand and then wash again.

Phil

 

Hi Alan,

I've built a couple of composite boats with wood, glass, and epoxy.





I'm sure you will be fine. You can add layers of glass and epoxy while the previous layer is still "green", not fully cured, and not worry about blush or sanding. In fact you will get a molecular bond instead of just a mechanical bond (which is still very adaquate). After 72 hours you should wash and sand.

Paul

 

Just to put your mind at ease... you can add acetone to West system epoxy to modify it's viscosity... I got this information from their tech department.... I've "thinned" their epoxy before so that it will penetrate further into wood. If the epoxy is thinnned... it just remains a little soft for a few days until all the acetone evaporates. So wiping the cured epoxy with acetone didn't do it any harm. Just sand and wipe it with water to remove the amines from the surface... this is done to insure better adhesion of the next layer of epoxy.. Good luck.

 

There are a number of people who believe that because you can not see the blush, you can not remove the blush. They tend to use no blush epoxies.

But I expect that you will have no problems.

 

I have built 2 kayaks,1 with system 3 1with mas,both nonblushing epoxy.They both worked great.built aBrown searunner 25' with west,had same problems.will never use west again,why do any extra work you dont have to

 

I've used West system for repairs and on wood components exposed to UV... that is how I got used to using West system.. they have a hardner with UV absorbers... I've never actually seen a "blush".. My understanding was for better adhesion of the next layer ( if the underlying layer was fully cured ) was to sand and wipe with water to remove any amines that may be on the surface.I'm using the 105 resin... I've been to the Gudgeon Bros. site and I've noticed they now offer a lot more resin formulations for vacuum infusion laminations. On the 105 resin system it is possible to apply more resin and cloth as long as the resin will physically "support" the next layer. What is your experience with the other epoxy resin systems?... Easy to mix and use? Any drawbacks?... I liked using the West resin because it doesn't go "off" like polyester... it just keeps getting thicker until you can't move it any more. Which works great for repairs.One more thing...are the other brand of resins as clear as the West resin... When I'm applying it as a barrier coat on exposed wood.. it is crystal clear and you can see the grain very clearly through it... I've noticed if clear gel coat is used... it appears "foggy".

 

When I built my last kayak I over tighend a few screws used time tickend MAS to level low spots, wored great. Only had blush once, high humidity day(west105). Same low viscosity resin,spreads the same ,typical pump for mixing,handles the same. Cost less,this is not cheap stuff . 30 hour recoat time, with no cleaning or sanding! Jim

 

You might try the new Silver Tip resin from System Three. Its a no-blush resin, with a very low viscocity and VERY clear.

Joel

 

Find this difficult to believe - attending WEST technical workshops, they stated that penetration is barely enhanced by thinning (something like 10% or less)
What they DO recommend is warming the epoxy (before mixing) to reduce viscosity.
Check it out yourself (989)-684-7286

True. Try bonding a small area to assure yourself that all is OK

 

I neglected to mention that how I was using the epoxy isn't something that West system epoxy was originally intended for. That was the reason for the reduction with acetone. I wouldn't recomend reducing it with acetone for boat building or lamination, but warming it like they instruct.