Bubbles, Blemishes, and Holes in first layer of fiberglass?!

[JimC3]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Oh no! It was a lovely day here so I took the boat outside for some epoxy sanding. I used the tip to paint a light coat and sand until smooth and it worked great! The problem came just now when I noticed the front part of the boat had the epoxy turn a strange milky color. Like this:

When I ran water over it it turned back to normal:

When it dries it gets milky again...
I'm quite terrified. The temperature was 65 all day and it sat in the weak Missouri sun. Did this cause the epoxy to change colors? Would sanding it help? After all that work I'm finally ready to work on the inside and to have that part do that is really scary.

Any help is greatly appreciated!

For reference here is the boat before I started fiberglassing it:


To have that hand carved stained wood to turn milky on me now is so scary!

 

[jigngrub]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Low temp/moisture/humidity is probably the culprit, depending on the type of epoxy you're using... 65*F can be a minimum working temp.

Applying epoxy in damp conditions isn't a good idea, between the dampness and the low temps it's real easy to get an amine blush.

Take the boat back inside and put it under some strong warm lights, like these halogen work lights:

Designers Edge L-13 Two 500 Watt Portable Halogen Work Light: Decor : Walmart.com

Heat and light should clear up your problem.


Winter is not the time to epoxy outdoors, or even in a cool damp basement. You need warmth and low humidity for a good epoxy set/cure.

Edited:

I just did a little searching and found this:

3. I applied epoxy outside under a covered awning but it rained last night and now the surface is cloudy and sticky. What do I do?

Caution must be taken when using epoxy in cool, humid conditions. Despite working under cover, if it rains while the epoxy is still wet, moisture contamination can occur and the epoxy may never cure properly. If this happens it will have to be removed by mechanical means, either scraping and/or sanding away the contaminated epoxy.

I found it here:
http://www.uscomposites.com/faq_epoxy.html#ts3

Like I said earlier, get some warm lights and try to dry that stuff out...quickly!... but some more 120 grit sandpaper may be your only hope if it doesn't clear up.

 

[JimC3]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Thanks for a quick response. I will certainly take it inside really quickly. The strange thing is I didn't epoxy that part at all. I sanded the whole boat and was so happy with the progress I decided to wash all the dust off and all of a sudden that part got cloudy. I'll try the lights but I have to smooth out the epoxy there anyway. Every time I sand it I get nervous. I suppose the pictures clearly show that I'm quite comfortable with wood work but the fiberglass and epoxy is a different story. I just hate getting randomly set back all the time...

 

[jigngrub]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Thanks for a quick response. I will certainly take it inside really quickly. The strange thing is I didn't epoxy that part at all. I sanded the whole boat and was so happy with the progress I decided to wash all the dust off and all of a sudden that part got cloudy. I'll try the lights but I have to smooth out the epoxy there anyway. Every time I sand it I get nervous. I suppose the pictures clearly show that I'm quite comfortable with wood work but the fiberglass and epoxy is a different story. I just hate getting randomly set back all the time...

Your epoxy probably wasn't cured completely and that's why it turned cloudy... you gotta have heat and light to cure that epoxy. It's also best to let each coat cure completely before adding another coat when working with epoxy in lower temps. Heat your work area up good and heat up what you're going to apply the epoxy to and your epoxy as well.

Summer time when it's so hot outside you can't hardly stand it is the best time to apply epoxy resin. I applied mine in 95*F heat and it still took 2 or 3 hrs. to dry and 24 hrs. to cure.

The next time you want to do anything with epoxy, you should PM me and ask for permission first.

 

[JimC3]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Your epoxy probably wasn't cured completely and that's why it turned cloudy... you gotta have heat and light to cure that epoxy. It's also best to let each coat cure completely before adding another coat when working with epoxy in lower temps. Heat your work area up good and heat up what you're going to apply the epoxy to and your epoxy as well.

Summer time when it's so hot outside you can't hardly stand it is the best time to apply epoxy resin. I applied mine in 95*F heat and it still took 2 or 3 hrs. to dry and 24 hrs. to cure.

The next time you want to do anything with epoxy, you should PM me and ask for permission first.

Haha. I am obviously depressingly incompetent with fiberglass. I just can't help but to keep thinking I destroyed a pretty nice wooden creation with inadequate fiberglass skills.

So when I sand that with the 120 grit it will become opaque from the sandpaper Scratches and dust. Is it safe to wipe it down with a water soaked napkin? I just so regret fiberglass sing over the stained wood...

Thanks for all your help!

 

[jigngrub]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Sand the epoxy carefully, if you start getting into the fiberglass stop and move to another section.

Wipe the sanded areas with a damp lint free cloth, turning the cloth frequently and rinsing the dust out of the cloth when it becomes full.

After you've gotten everything sanded and wiped down you can apply another coat of epoxy to the boat. Make sure you work area and materials are warm (read hot) if you can get your work area to 80*F it will help.

The new coat of epoxy will fill the sanding scratches and make the epoxy coating clear again.

Do you have enough epoxy for another coat?

 

[JimC3]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Ok thanks, that's good advice. Unfortunately no. The resin is totally out. Should I wait to sand until I get more resin or can I go ahead and sand now? When I resin next I'll drag a heater and some halogen lights over to the area. I was a fool to take it outside today anyway. The only thing Missouri is known for is unpredictable weather...

 

[jigngrub]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Go ahead and sand it now... after everything is dried and cured.

How do you plan to protect your epoxy coating from UV break down? Or did you use a UV inhibited epoxy?

 

[JimC3]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Ok thanks. I was instructed early on to buy some sort of marine UV protective coat and apply it to any areas where the epoxy is directly exposed. I was not given a brand though. Do you have recommendations for a brand and where I could find it? I suppose a deck sealer from Hole Depot won't work...

 

[jigngrub]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

You can use 3 or 4 coats of exterior grade spar urethane like the Minwax Helmsman:

Helmsman 1-Gal. Satin Spar Urethane-13205 at The Home Depot

... about $15 a quart at Wal-mart or Home Depot and you'll still have a fairly clear finish to show off your stained wood.

If you don't get into your fiberglass cloth too much when sanding the epoxy again, you may just want to go ahead and start the exterior grade spar instead of buying more epoxy. There's a working temperature range on this stuff too so you'll need to apply it in a warm area too.

 

[JimC3]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

That's very interesting. Great tip. So essentially I can sand down the epoxy and instead of buying Raka's $80 epoxy I can just finish off the bottom with the exterior grade spar? And it will still be clear? That almost sounds too good to be true!
Thanks again for all your help! I can't tell you how much I appreciate it!

 

[jigngrub]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

The urethane does have a little bit of a brownish color to it, kind of like a tint... but it is clear. A minimum of 3 coats for exterior exposure as per the directions.

Sand your boat carefully and pay attention, if you start raising the glass fibers move to another spot.

 

[Gator1996]

Re: Bubbles, Blemishes, and Holes in first layer of fiberglass?!

Jim
Looks like too much resin to me.

I am curious what tool you are using to wet out the glass? And how large of a section are you laying up at a time? The poly that most of us use kicks so much faster than epoxy so we do smaller layups as a rule. With epoxy, I think I would drape the cloth over the hull, smooth out the wrinkles and pour the mixed epoxy over the glass, then use a spreader/squeegee to move the resin into the dry parts of the cloth at the same time bubbles should smooth out also. I am thinking surfboard; you can probably find some shaper/glasser videos on youtube.

If that is how you have been doing it then I am clearly no help. Good Luck in any case.