hi guys first of all i don’t speak english well so i hope you can understand me anyway… i’m building my first surfboard but i made a mistake in the process of hotcoat…i mixed only waxed styrene in my poliester resin without mekp…it took a while to the resin but at the end it hardened anyway (i dont know how though) …the question is: do i have to fix it? and if yes, how? maybe sanding as much as possible to remove the wrong hotcoat layer and retry ? simply add a right hot coat layer to the wrong one? leave the board as it is and ignore the problem and sanding it ? any other suggestion ?
Did you post this in ‘errors and bugs’ on purpose?
I haven’t used poly in so long, I can’t say for sure, but I think a hot coat on top will take care of it, as I did that once making a snow board about 35 years ago…
If there was no catalyst in that batch I can’t see how it could have hardened. Resin will harden all by itself but that takes months. Anyone who’s left a can untouched for a long time will attest to this. Even then, that won’t happen unless the container isn’t closed tight.
To solve your dilemma, just apply another thin coat and mix it a little on the hot side. That is, increase the catalyst ratio by a small amount
thanks you all for the answers… i’ll apply a further thin layer then …do you think it is better to do it without sanding the wrong one?because i think the board will be too heavy…
how much increment of catalyst ratio should i apply? when i laminated i used 1% of catalyst in weight…do you think 1,5% it’s ok for hotcoat?
… for the resin i also think it’s a “uv cured” even though the supplier told me not when i asked him… that’s why he gave me a catalyst… however even when i laminated ,the resin hardened only when i putted it on the sun… so i’m pretty confused about my resin now because if it is uv cured resin the hoat coat is ok without mekp right?
I bet he put on the hot/fill coat when the lam was still tacky which is usually the suggestion. Probably som of the MEKP from the lam coat was absorbed into the hotcoat to kick some but not all of it.
Like everyone said make a super hot coat and sqeegee that into the current soft non catalyzed fil which should help to get it to “kick” but you still may ave some problems. You need the new “hot” hotcoat to get into and mix with the old coat.
Don’t worry we all have our “brain fart” moments
in our family we call them “oh sh*t” moments
my brother even had pendant he wore to celebrate them.
my supplier is sure the resin is not uv cured and sustain the oneula’s theory…it hardened due too the previous mekp in the laminating process. ( however i find it weird because i’m sure it was non tacky laminated layer…but it is the only explanation so i think i have to ask your brother his pendant xD) i guess that little amount of mekp is not enough to consider my hot coat “good” so the only thing i have to do is add a new layer of hot coat(** with 1,5%catalyst maybe?or more…i don’t know**)…i will try to sand away the wrong one too…
…worst if you still had a soft layer but if you have a hard one no matter if it s tacky spots, grab a rubber block, coarse grit paper (50 and in some cases, like between fins, with 36) water and dish soup; use your elbow grease no by machine and start to sand. In first hand you ll clog the sandpaper a bit then you ll see how easily you can sand. After completed, do the same with an 80 grit one, then gloss coat.
ok i’ll sand as you suggest… but then you are saying to do a gloss coat instead of a second layer of right hotcoat? what is more important a “well done” hotcoat or a layer of glosscoat?
The hotcoat is also called a sanding coat. Its main purpose is to allow sanding the glass job out to a smooth, even finish before the final sealer coat of resin or spray finish. Done properly, a hotcoat is sanded away for the most part. Guys who are experienced laminators use a minimal amount of resin for their hotcoats because most of it gets sanded off and extra resin is just a waste. Do as I suggested, if your current layer is sticky. Add a thin hotcoat, sand it, then finish however you please.
all right guys …you have been very helpful…i will add a thin hot coat with 8 ounce of resin 2% of catalyst, 5% of SA even if the previous one hardened well. no gloss coat (too much weight ). thanks you all