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Mr T

Do you prep between epoxy coats?

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I just put a coat of flex coat thin build on a couple repairs I did for some rods, but am not going to be able to get a chance to add a second coat till likely two weeks from now. I've heard about finishes not adhering to each other if given more than 24 hours cure time. Do I need to do any kind of special prep for the second coat?

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I wouldn't wait that long but if you must , I would scuff up the first coat with very fine sandpaper or fairly course steel wool. I think you can miss a day or even two but 2 weeks is a long time.

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I have not had any problems whatsoever puting a coat of epoxy on after waiting sometimes a month. I get sidetracked sometimes and by the time I put a second coat on time has passed. I have done this several times with no ill effects noticed. I did not do this with your brand however. It's really not much trouble at all to do as Saltheart says so if you're worried about the results I would sand between coats. I have had success my way, so until it fails I will continue with it.

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i have let them sit before putting in a second coat. i just wipe it down with alcohol to make sure its clean and have not problems. if you use sand paper be careful you dont go thru the 1st coat in any spots and fray the line

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View PostI wouldn't wait that long but if you must , I would scuff up the first coat with very fine sandpaper or fairly course steel wool. I think you can miss a day or even two but 2 weeks is a long time.

 

 

 

Yeah this is not by choice, got to travel for work and well, you know the rest..

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You will not notice if the long wait has caused an adhesion problem until sometime down the line. I think it takes time for expansion and contraction and possibly sunlight to do its thing. Eventtually though , you will start to notice flaking or very minor bubbling. The trouble is its minor for a long time and it adds up to a ruined finish. I think its best to scuff it up if you have to wait. I think I would prefer doing the second coat too early rather than waiting 2 weeks. Like even 8 hours later if it cure to the touch.

 

I understand sometimes life and work get in the way of the fun stuff like fishing and rodbuilding. The crosses we bear! smile.gif

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I understand that Saltheart. The rods I was talking about have been in use for some time now with no change in the finish. All it's gonna take is the finish getting ruined one time and I'll no longer wait so long. Ideally I like the second coat the next day...doesn't always work that way though. I'm not reccomending anyone do it this way, just relaying my experience.

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View PostYou will not notice if the long wait has caused an adhesion problem until sometime down the line. I think it takes time for expansion and contraction and possibly sunlight to do its thing. Eventtually though , you will start to notice flaking or very minor bubbling. The trouble is its minor for a long time and it adds up to a ruined finish. I think its best to scuff it up if you have to wait. I think I would prefer doing the second coat too early rather than waiting 2 weeks. Like even 8 hours later if it cure to the touch.

 

 

I understand sometimes life and work get in the way of the fun stuff like fishing and rodbuilding. The crosses we bear! smile.gif

 

 

Is this not a standard thing to do? Sometimes I put on a second coat 6 hours after the first. Has anyone done this and experienced problems later down the road? I hope not. redface.gif

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yep , whatever works is fine. I remember working on the hull of my sail boat. I had a spot that needed a repair. I did some woven roving I think its called Very coarse weave) , then some tighter weave and finally some very smooth weave layers. Anyway , sometimes between the paters would get hard a rock but still had a tacky surface. One thing I discovered was that if I sumply washed the surface with an acetone soaked rag , the tackiness instantly hardened. I mean right before your eyes. the problem was it went dull looking at the same time. Since these were inner strength Layers it didn't matter and the outer polyester layers cured just fine. There are a lot of tricks and every little detail could be why something works for one guy and not another.

 

The classic story , and its humorous, is the guy who went to his new car dealer and said his car got vapor lock and wouldn't start if he ate vanilla ice cream. smile.gif It turns out , this guy would take a short ride from home , run into the store and buy ice cream , if he bought vanilla the car wouldn't start but if he bought chocolate , the car started fine. They finally figured out that the short ride to the store coupled with just a minute in the store caused the vapor lock but after 5 minutes waiting the car would start fine. Well the vanilla was in a freezer right neat the register while the chocolate and all other flavors except vanilla were in the big freezer which was along the back wall of the store. Ihe had to walk through tye store , find the flavor he wanted and then walk back to the front and pay , the vapor lock disappeared because that took 5 minutes. The 1 minute trip in , garb the vanilla and out didn't allow time for the vapor lock to dissipate. True story too. I always liked that one!

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If you put it on too early , you will see the problem right away , not down the road.

 

Most guys let them cure overnight, so maybe 12 hours say. I like to do finishes just before bed and the second coat again just before bed the next day so that's 24 hours.

 

I have done some rush jobs with 1 coat at night and a second in the morning after I woke up. I like waiting longer but shorter is OK as long as the finish does not move or wrinkle at all when you apply the next coat. I have seen some finishes that wrinklr just like old skin when the second coat is applied. I don't know why but assume it is because the first coat was still not cured enough to protect it from the solvent in the second coat. That's pretty rare and could be unique to just certain types of epoxy or polyester finishes

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Why not wait to put that 1st coat on when you get back? Why do you have to put a coat on now?

 

Wait and do it right when time permits.

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View PostWhy not wait to put that 1st coat on when you get back? Why do you have to put a coat on now?

 

Wait and do it right when time permits.

 

 

I did the first coat and then got sidetracked at home with that thing we called life and work. The traveling was a last minute thing, not planned.

I have a long range trip out of San diego coming up in August and have had these rods needing the repair for months. They're not mine so I want to get them done before things get even crazier. The next few months are very tight, so thought I could sneak it in. Shows me, that's what I get for thinkin'...

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Definitely scuff as Saltheart says!

I like to use Scotchbrite though. It comes in a few grades (grits so to speak) and I use the green for this.

You can also cut it into little strips to get in between guide feet and pull it back and forth like a length of string (be careful!!).

You want to gently scuff till you remove ALL the gloss, but no more than that.

Tape off just outside the ends of your wraps so you scuff completely over the present finish right down to the blank. When you do your next coat, just overlap onto the blank so you encapsulate the last coat.

When you do not scuff, a decent chip on the edge of the wrap can cause the top coat to start to peel away.

Most of these thread finishes are basically casting resins and they will just sit on top of something smooth with modest adhesion...

Unless you give it some sort of texture (tooth) to grip into.

If you do this, you can get a very decent bond that can take some pretty decent abuse.

Have a blast on your long range trip!

Which fleet are you going out with and which boat?

 

Thanks,

 

John

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John, we're doing a two day on the pacific voyager. A buddy put the trip together; we booked the boat, so it's all people we know which will be cool.

 

Really looking forward to it, never done a trip like this!

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