2nd hot coat peeled off like skin? PU/PE

i tried to add some weight to a board of mine, and thought i'd use some hot coat resin i found in my shed. I brushed it on, then brought it out into a cloudy day. It seemed to kick ok ( felt warm etc ). When i started sanding it though some of it wanted to peel of, so i left it overnight. This morning i went to sand some more, and i lifted a small section with my hands, a huge section peeled off like skin!!. i then peeled the rest off ( why not? ).

 

THe board was sanded to a 400 grit finish. My guesses are :

1.) The board was too smooth?

 

2.) The UV cure resin wasn't kicked.

 

Weird coz the resin definately felt kicked, although it was a cloudy day, but i've done it before on cloudy days no worries.

 

Any thoughts??.

 

Cheers

[quote="$1"]

i tried to add some weight to a board of mine, and thought i'd use some hot coat resin i found in my shed. I brushed it on, then brought it out into a cloudy day. It seemed to kick ok ( felt warm etc ). When i started sanding it though some of it wanted to peel of, so i left it overnight. This morning i went to sand some more, and i lifted a small section with my hands, a huge section peeled off like skin!!. i then peeled the rest off ( why not? ).

Any thoughts??.

[/quote]

Any thoughts

Lead to many thoughts

Of skin that peels, napalm's sinister intent (better to be a fan of beer!)

Battlefield compassion a bitter and weighty harvest

Weighty, a surfboard sheds its skin, weighty no more

emerging old and smooth from its coccoon

Wear lead booties

Problem solved

(apologies to Ambrose LOL)

 

try sanding with 100 or 120 and then do it agian. 400 is much too smooth. also, contamination such as oils, wax, and other debris may have caused it. thats my guess. good luck

You had old wax residule. You need to clean with acetone, then sand with 80 grit.    The sanding resin will stick to the 80 grit scratches.    Don't make it so smooth next time?  The resin needs something to bond to.

It funny how guys (not you) won't sand the board enough to get the lumps out, but will sand a hot coat to 220 or 320 grit.  You need to leave enough rough up to have the gloss coat stick.

I usually only sand the board to 100 grit, then I put the gloss and then polish it out. Any higher grits is just a waste of time and effort.

Cheers guys. Resinhead it was the bottom, no wax there.

Good work huck!

Will sand with 100 grit next time. The upside is my board is very clean for the next time haha. Will probably wait and do a glass patch in the first 6-8''. Will remember to sand though.

 

 

Cheers all.

All of the above, except the Ambrose type prose.  Sanded too smooth for one thing.  You said the resin was old for a second thing.  You keep referring to "cloudy day" ; Are you inferring that the resin was UV?

Yea… sounds like a sanding issue. I sand to 80 grit and that’s it. The only other thing I can think of would be contamination on your sanded surface. Oils, waxes, etc… But if it was freshly sanded, that’s unlikely.

Had the board already been surfed? It sounds like contamination. Normally resin will stick to a surface sanded to 400 grit, no problem. -C 

     Howzit beerfan, I have to agree that 80 grit is probably the answer. Aloha.Kokua

I glassed a 5'' x 7'' patch onto the nose today, same resin, but i scuffed the surface with 100grit first. Worked fine!.Must have been too smooth. Very sunny day too, so the UV kicked quick. Now to see if the patch has added a little bit of extra weight in the nose. Looking like waist high tomorrow, hope i can use my little 5'8'' and test the theory.

 

I have surfed this board, but not for a week or so. I suppose salt water may have been on the board, though that would be on the deck as well, and it worked fine today. Weird, anyway it worked so thankyou for your help

 

Thanks guys.