Bottom lam with RR yellowing

General Discussion
1

I start noticing a brownish yellowish color that follows the bottom laminate trim after I hotcoat and sand. What is the meaning of this? Using resin research epoxy

2

could it be rust?

rusty razor? scissors?

what do I know…

3

very susceptible to uv. Keep it out of the sun.

4

Hasnt even seen the sun. Thats why its so strange. 

5

Weird. My guess is incorrect mixing ratio. Are you measuring by weight or volume? Or is it old resin?

6

[quote="$1"]

very susceptible to uv. Keep it out of the sun.

[/quote]

No. RR fixed those problems about 5 years ago

7

[quote="$1"]

Weird. My guess is incorrect mixing ratio. Are you measuring by weight or volume? Or is it old resin?

[/quote]

You can mix by weight or by volume and get a quality result. Incorrect mix ratio can happen with or without a scale...more likely to get resin that doesn't cure with a bad mix......Old resin...well...the old Resin Research yellowed...fast.......but they fixed that problem.

No photos at this time????? Did you spackle the blank? Did you thin the spackle?

Rust or maybe tape left over from the cutlap???? I don't know. Cat piss? who knows......I thinned my spackle with bottled water one time. That board has all kinds of wierd stuff going on...brown stains under the glass. Looks like hell. Thin your spackle with DI water or distilled water.......Ray

8

If it’s only along the trim edge (cutlap I’m assuming?) it’s gotta have something to do with the tool you used to trim. Or if you faired the edge, what you used to fair with. Otherwise, it would show up everywhere.

9

We glass 100’s of boards with RR and it’s a good product.

  1. Your Epoxy could be old?

  2. Did you use distilled water to thin your spackle?

  3. Are your tools clean?

  4. Did you weigh your mix?

Kind regards,

surfding

10

You know what I’ll do I’ll shoot some photos over when I run back over to my glass room.  But I think the suggestion about the tools being dirty (air grinder) could potentially be the problem.  I’ll get some photos

11

If you used your die grinder?—  Did you install a fresh or cleaned disk??----  or — Did you just pick up the grinder with a disk that had been used previously and may have been gunky???  I’m not supper exsperienced with Epoxy but;  I know that that if a sanding disk gets gunked up from soft cured resin and you use that disk on another lap It will heat up and spread to the current lap you are grinding.  Just the heated resin will burn the lap.  You may have also over ground the lap.  Heat would turn it yellow.

12

I used to have a similar problem, but mostly with poly boards.  It was caused by the solvent I was using to wipe the freshly trimmed or ground lap.  If I used acetone I got a yellow or brownish haze along the the lap where the acetone must have saturated exposed fibers in the freshly ground lap.  I believe any solvent on any resin could do the same thing.

13

heres the board how it came out. sorry that the pic isnt all that great but you can see the tannish color in the board.

728×544 59.3 KB

14

Nice looking SUP.  Hell!  I’d like to have a short board with that outline.  Lowel.

15

Thanks McDing. You helped me get there with answering all my annoying questions.