Filling Fiberglass Weave

[Robert Cox]

We put the sealer coat of epoxy on the deck yesterday and intend to lay the fiberglass today. Tomorrow we will apply another coat of epoxy to fill the weave.

I know this has been discussed before but my brain must have dumped the file. (I can't remember) What is the best filler to mix with epoxy to fill the weave of the fiberglass and get a good smooth finish.

Woodflour, silica, microballoons or other.

Thanks

Bob

[capt jake]

A dab of silica and the bulk of it filled with microballoons. It will take several coats to get it 'truly' smooth.

[JTam]

Yes, use microballons and silca. Microballons by themselves won't act as a thickner and it'll run on vertical surfaces. Also, I used a cabinet scraper, available from woodworker stores, between coats to remove the high points. Whether you use a scaper or sand, do it as soon as the epoxy has set up - not tacky, and sandable (doesn't form gummy clumps on sandpaper). If you wait too long, especially with silac in your epoxy, it will take more effort to sand it smooth.

One last note, you need to finish with a coat of epoxy without microballons to proper seal the finish.

[Robert Cox]

Thanks guys, I'll buy some microballoons and silica tomorrow at West Marine. I'm hoping it dosen't take too many coats. I was hoping for two more coats tops to fill and fair. Is this too much to expect?

Bob

[Barry Pyeatt]

I think that all depends upon how fine a finish you are going for. If it is like an automotive finish, it is likely going to take a lot more.

If you are going for a nice gelcoat boat finish, two should be more than ample based upon your prep work and glass work. 8)

If you are just wanting good protection and to have a nice looking 10' finish then maybe one will be enough.

Think it also depends upon just where your satisfaction level is at. And just how AR are you about the finish. :wink:

There are a couple builders out there that have Grand Piano finishes on their boats and may be afraid to put them in the water. (No names or inferences implied toward any one particular person. ) :roll:

[Robert Cox]

Well Barry, I gave up on the Grand Piano finish a long time ago, but 10' or less finish would be nice. The deck isn't a problem do to the non-skid but the cabin coaming, the seatbacks and the cabin bulkhead is where I would like a nice finish.

When finishing the hull I found that epoxy alone would not give me a finish I wanted without a lot of sanding. Sounds like what I need to do is give everything a good Microballoons and silica coat and a final epoxy coat and then work on the seats, bulkhead and coaming to get the finish I want. They may need extra coats but their combined area isn't that great.

The cabin coaming and bulkhead are my greatest worry. I need a good fill coat that won't sag.

Bob

[Robert Cox]

Has anyone tried the epoxy fillers from Interlux? Could this be used to fill the weave?

I'm looking a $30 for the silica and microballoons or $69 for the epoxy filler.

Here's what they say about it:

http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&productId=72272

Interfill is a two part epoxy putty designed for fairing and smoothing a surface where a fine finish is required.

-Can be used above the waterline to the surface prior to applying topside finishes

-Can also be used below the waterline to fill blisters and as part of a keel fairing system

-If it is used below the wateline, it must be overcoated with four coats of Interprotect 2000E/2001E

-Cured epoxy has excellent solvent resistance and will not be attacked by strong solvents

-100% high-solids epoxy fairing compound

-Lightweight, mixes easily, trowels out smoothly and is easy to sand

-NOTE: Replaces 417/418 Epoxy Compound

-Drying: Sanding: 6-8 hours @77

[Frank Hagan]

Has anyone tried the epoxy fillers from Interlux? Could this be used to fill the weave?

Yep, any epoxy fairing compound could work well to fill the weave, then sand smooth. Then, roll on a couple of sealing coats over it with a very short nap foam roller (1/8" or so ... not 1/4", or you'll just get bubbles!) and paint.

I had some epoxy fairing compound from Fiberglass Specialties which was wonderful to use. I never could get the same consistency with mixing my own, unless I was using wood flour, but wood flour is harder to sand (and Capt Jake can tell you ... that's NOT GOOD!)

[Barry Pyeatt]

Bob,

We have used the Interlux product on a number of projects. Most of them repairs and I think all of them were on glass. Most of the repairs were epoxy resins. Above the waterline it worked great. So on your deck and cockpit/bulkhead/seats it should give you good results.

Below the waterline, on a boat that will remain in the water, it really needs the additional barrier coating before the final finish. Lots of additional work for not much in my mind.

I would also say that fairing surfaces with wood flour and epoxy is just too much work. But I give Capt. Jake all the kudos in the world. His finish is darn near Grand Piano. Certainly coffee table. :roll:

But then we have had excellent results with microballons and a little silica. Smooth and little difficulty sanding it to what ever finish you like.

[Brent]

U.S. Composites http://www.shopmaninc.com/fillers.html make a SM fairing compound that works great. Mix it to your liking with epoxy resin. Good sag resistance and its easy to sand. Fairing the hull on a weekender will require about 5 qts, setting you back a whole 10 bucks.

[Craig]

Bob, unscented baby powder works well for small areas.

[Robert Cox]

Frank, where does a person find 1/8" nap rollers? The shortest I've been able to find is 1/4".

I'm off to lay more fiberglass.

Bob

[John Teetsel]

Glen-L has 7" short nap rollers especially for epoxy @ 2.49/pair http://www.glen-l.com/supplies/appli-supplies.html

Jamestown has 7" @ 2.07/pair and 9" @ 2.22/pair http://www.jamestowndistributors.com/cgi-local/SoftCart.exe/store/entries/index_paint_supplies.html?L+scstore+zhyv9128ffc893c8+1056858118

I like Glen-L microballoons, 4.77/lb, because they're white as opposed to the purple/brown fillers found elsewhere. If mixed with a little sanding dust, you can match the color of your wood very closely.

http://www.glen-l.com/supplies/fillers.html#

[Frank Hagan]

Frank' date=' where does a person find 1/8" nap rollers? The shortest I've been able to find is 1/4".

I'm off to lay more fiberglass.

Bob[/quote']

West Marine and RAKA.COM have them. I bought several from RAKA, and then when I ran out bought from West Marine .... WM was more expensive, of course!