first time builder needs help with epoxy finish

Builder's Forum
1

I'm building a Eastport Pram.  Things were going good till it came to it came to coating (painting) with epoxy.  I got a bad case of curtains (runs) and ripples.  I rolled it on, brushed over twice, looked real good...till I came back the next day.  Got worse with each coat.   I'm sanding them out and need to do another epoxy coat, don't want a repeat.  Not sure why, didn't feel like I put it on too thick.  Could it be that I didn't let it cure enough?  Left it cure more than overnight, less than 24hrs.  My shop (basement) stays at 60 degrees.

Any suggestions on smoothing the runs off.  I sanded, but went through the epoxy at places.  A scraper?

Thanks,   Jim

2

Wanted to get back to all.  This is what I did.

Warmed shop to 65deg, warmed resin & hardner a little more.

Spread as thin as possible, brushed over a number of times.  Didnt' even 100% cover.  And rebrushed till things got stickey.

Still sagged and rippled.  Very discouraging.

I called Mas for advice.  The only additional suggestion from the teck support guy was to thin with denatured alcohol.  This I did, 1/4 oz to 5 pumps, added a little more as needed.  I am happy to report that this worked for me.  Finish was very good.  Realize that I'll need an extra coat, beats sanding.

My advice to first time builders is.  LEARN FINISHING ON A SCRAP FIRST.  At least on the seat bottom.  You may waste an hour, you may save many hours of hard work repairing a bad finish.

Jim

3

Thanks for the advice.  Ordered the cabinet scrapers, they came saturday.  Just the right tool.  Surprised how thin the finish is between the curtins.  Now hopefully I can give it one more coat of epoxy and the finish will be good.

4

I use a cabinet scraper to elimnate runs and drips..  I scrape down to almost flush, and use my sander or hand sand flush.

http://www.rockler.com/product.cfm?site=ROCKLER&page=4898

I like to have the shop temp at 85 degrees with falling temperatures to reduce bubble formation.  After I apply a fill coat on the hull. I still hang around 10 minutes or so to clean up any drips.

Let us know what kind of roller and brushes you are using?

5

Thanks for the replies.  I use short nap rollers and 2" chip brushes from Jamestown Distributors.  Think that my cool shop could be a problem?

6

http://www.jamestowndistributors.com/userportal/show_product.do?pid=2518&familyName=Epoxy-Plus+Roller+Cover

Are you using polyurethene rollers, designed for epoxy?

Could you be in a rising temperature situation that reduces the viscosity of the epoxy?

When using rollers I do the following in applying epoxy fill coat;

1) First I brush on epoxy by pulling my brush across the hull, beam to beam. (one to two square foot area)

2) I then use the roller to spread a thin coat end to end.

3) Finally, I use a chip brush at about 45 degree angle and lightly tip off the bubbles caused by the roller, brushing end to end..

7

After 6 boats and my share of resin runs and my present passagemaker build a few suggestions.

1. Use quality foam roller (CLC has great ones)

2. Tip out your work with a quality foam brush

3. When you think you have it spread thin enough it probably is NOT

As resin gels it the viscosity drops before it gels.

Drips and runs must be removed prior to recoating.

Fresh MAS epoxy will cure fine @ 64 degrees.  You will have to wait longer before sanding.  I like to use scrapers to remove errors while resin is still green. Save a lot of fuss later.

Last check you work frequently for the first 3 to 4 hrs of cure.  Once it starts to cure If sticky it is too late to feather runs out. You will have to wait until at least green to scrape off.

 

8

Your comment about rebrushing until it got sticky may be the key to your problem. Epoxy work should be done quickly: roll it on, squeegee off the excess, and leave it alone. You will find your next boat a lot less stressful.

-Wes