oily film on inside of vaccum baggin plastic=epoxy problems???

General Discussion
1

just finished glassing 2 boards...

Whitehot EPS, Resin Research Epoxy, 6 oz E glass...

while glassing them, i had a hard time getting the glass to stay down in places, even in the flats. it kept rising up and creating air pockets below the glass.

i've only glassed 1 1/2 boards before now and never had this happen (had other issues but not this one, hence the 1/2--major melt down on #2 when trying to glass in really hot temps). after reading through the archives, it sounds like i had a contamination issue. but, i couldn't figure out what had gotten on the blanks. i was meticulous about keeping them clean, never touched them without clean gloves on etc, etc. these were the first 2 boards that i used a new airbrush on but, the contamination was all over, not just where i had airbrushed. i used my craftsman air compressor to blow the blanks off but, my compressor is oiless...

i couldn't figure it out until, i rubbed my fingers on the inside of the poly tubing that i got for future vacuum bagging. my fingers came away with a really light oily film that made my hands slippery. anyone ever deal with this? i had wrapped the boards in the plastic to keep them protected during transport to the place where i was glassing. that's all i can figure. i'm sure some of you doing vac-bagging have used this poly tubing before. any issues?

i'd like to isolate the problem to prevent future issues.

help please...

2

were the bubbles inside the bag against the lam coat ?, always after i lam a side i put perforated sheet then a 2oz. breather fabric then slide it into the bag and vac down to 5to 7 "

3

Contamination issues don’t usually show up when you’re glassing with cloth, its when you’re hotcoating/glossing that you see resin seperation.

Of course contamination whilst glassing is still a bad thing, its just harder to see.

More likely you were glassing on a rising temperature, and the EPS was outgassing. That defninitely creates air bubbles under the lam.

4

thanks for the responses guys...

lakewakes, i wasn't vacuum-bagging, it was normal hand lamination. i just used the bags to transport the boards from my house to a friend's garag to glass.

KKSurf, i hadn't even considered out-gassing. i will definitely read more in the archives about that... after the major meltdown on my second glassing attempt, i went out and bought a thermometer to keep with my glassing supplies. this time around, i was glassing 2 boards at the same time. i did the first lamination at 9pm and the temp. was at 83* F. it had been a warm day and throughout the night, the temp. slowly dropped to 70* and stayed there for the rest of the glassing jobs. the temp didn't rise above 75* again until the last hotcoat had been applied around 5 am. so, while the temp. wasn't falling that much, it was slowly falling throughout the lamination process. could out-gassing still be an issue? i just had a question pop into my mind, does out-gassing happen on the first lamination coat? i'm wondering if the air between the EPS beads would try to out-gass through the lamination or take the path of least resistence out the other side of the blank? i would think that out-gassing would happen more on the second lamination coat? again, i'll have to go through the archives and read up...

here's some pics. sorry for the quality, these are the best that i could get. i had to get real close:

this happened where there was color and where it was just clear. it was just easier to photo in the color areas... if i pushed down with my squeege, i could get the glass to lay down. then, i'd leave to go work on the rails or whatever and a few minutes later i'd come back and it would be back like this again.

being that this is only my 3rd and 4th glassing attempts, i'm not ruling out operator error by any means. but, i didn't have THIS problem on previous glassing attempts...

5

Hmmmm thats not a problem i’ve had before, sorry man…

Sounds like you glassed at the right time and everything. I guess contamination could be the thing. If there was an oily film on the plastic, maybe the board could have got contaminated badly enough that you got a crazy reaction like that! I dunno, just guessing now :slight_smile:

 

6

hmmm... thanks for the help.

before i glass the next one, i wil have to do some test patches.

7

I’ve never seen an oily film on any of the bagging film that i’ve bought, I wonder what it was?

Epoxy is really touchy to contamination, so anythings possible I guess?

8

That looks like pin air, probably caused by one or all of the following: not sealing the blank, too dry of a lam, and/or outgassing.

 

Outgassing can also lift areas of cloth. More of a problem on the second side, as that encapsulates the space.

 

Some guys poke a hole in the cloth- where the leash plug will go- to act as a vent, especially if its warm.

9

oooh, "to dry of a lam"... there may be something to that... i was trying to get a tight, light lam and pulled as much resin as i could out of the lam thinking that that would do the trick. i sealed the blank as per the archives here on Sways. if i am able to rule out outgassing the temperatures being what they were, a dry lam being the issue, makes sense... when i pressed down, all the little pockets in the glass got filled, when i walked away, the glass 'puffed' back up and created those pockets again by the time i got back... hmmm... i am going to do some tests with the "oily film" on the inside of the bagging before i glass again though just for my curiosity. when i ran my finger on the inside of the bag and it came away oily, it was kinda alarming. especially after i had taken so much care to keep blanks clean... this is all really interesting...

thanks for taking the time to look and share your knowledge Allan and KKSurf... and thanks Mike for Swaylocks. without this place, building my own stuff would not even be a possiblity.

10

I agree with Allen.....

I think the oily bag is a bad thing but the problem you talk about sounds like out gassing. Hard to say....In the summer I do over night glassing just like you.The temps sound good.... Oh...the oily bag...who knows....

So....... I lam this EPS board and the bottom go's perfect...wait for the epoxy to cure...flip the board using wax paper so my hands don't touch anything...Two layers of cloth on the deck....getting the same problem your having.....Ray running around going crazy with a razor blade and a squeege making relief cuts ,ect......Ugly....the board came out fine ....then there's the time I tried to install a leash plug in EPS foam when the temp was rising from 75F to over 85F..........

Fun Stuff... all this foam and resin and fiberglass

11

looks more like a dry lam to me

I think the blank was sucking in the resin and you were pulling off too much