Fairing mixture.

See our FAQ and tutorials before posting.
User avatar
OrangeQuest
Very Active Poster
Very Active Poster
Posts: 2352
Joined: Tue Aug 28, 2018 1:14 pm
Location: Houston, Texas

Fairing mixture.

Post by OrangeQuest » Wed Jun 05, 2019 8:31 am

Just ordered the micro balloons to mix with epoxy for my fairing tasks that are coming up. Is it ok for me to use wood flour in with it when I need to stiffen it up for vertical applications? I have plenty of wood flour but no silica.

Reminding that I am on a very tight budget! 8O


"that it isn't just an ordinary sort of boat. Sometimes it's a Boat, and sometimes it's more of an Accident. It all depends." "Depends on what?" "On whether I'm on the top of it or underneath it."
A. A. Milne

fallguy1000
Very Active Poster
Very Active Poster
Posts: 3653
Joined: Tue Jan 12, 2010 12:25 am

Re: Fairing mixture.

Post by fallguy1000 » Wed Jun 05, 2019 8:40 am

I have to disqualify as I have never used wood flour.

I can offer this much. Both wood flour and microballoons are coarser and you may end up with a very rough surface that will require neat coating. And that is 2 oz per sqyd of epoxy plus lotsa sanding.

Even a microballoon and cabosil surface can get holes.

I have a feeling you will struggle to get a nice smooth finish.

But I could be wrong on my lack of experience.

If you have trouble, Quikfair will fill in all your rough spots.

I run quikfair over everything at the end. That costs more than the silica..
My boat build is here -------->

viewtopic.php?f=12&t=62495

User avatar
Capt UB
* Bateau Builder *
* Bateau Builder *
Posts: 2741
Joined: Mon Jan 03, 2011 7:12 pm
Location: DeLand, Florida
Location: Central Florida USA

Re: Fairing mixture.

Post by Capt UB » Wed Jun 05, 2019 9:09 am

Would need an expert to cover me on this, but you should be fine. After you have gotten the surface faired, you will be covering it with a two part epoxy primer.... Then paint....
><((((º>¸.•´¯`•><((((º> ¸.•´¯`•.¸¸><((((º> ¸.•´¯`•.><((((º>

terrulian
* Bateau Builder *
* Bateau Builder *
Posts: 2697
Joined: Sat Dec 07, 2013 11:29 am
Location: Marin County, CA
Contact:

Re: Fairing mixture.

Post by terrulian » Wed Jun 05, 2019 10:37 am

You will probably get a lot of 2 cents worth on this one, so here's mine:
I am much less a fan of Quickfair than is common on this list. It's expensive but what bothers me more is that I like to blend to the viscosity I want for whatever I'm fairing and Quickfair's thickness is set. For 90% of fairing I find microballoons work fine, mixed to whatever consistency I want. Wood flour is little harder to sand and if I needed something to prevent sag I used cabosil, which is expensive...but I didn't need it that often. And, actually, they're all a bother to sand...just have to get on with it, no magic.
I'm not sure about pinholes. I had some problems with them but only in specific areas that I must suspect suffered from something I did in the original application of whatever fairing I was using at the time.
I have a feeling that each builder is going to have to find his own way on this one, despite the fact that a lot of guys will tell you what the perfect formula is. Except for the original assembly, I found this true of the entire build from fairing to final paint. I had to just work it all out myself, You Tube and books notwithstanding.
Tony
Image

piperdown
Very Active Poster
Very Active Poster
Posts: 915
Joined: Fri Jun 22, 2018 12:35 pm
Location: Kansas

Re: Fairing mixture.

Post by piperdown » Wed Jun 05, 2019 11:07 am

I can't recall who it was but they used woodflour for fairing. I'm irritated I don't recall who it was because they just posted in the past week. It was specifically on their gunnels.

As far as a mix and sanding...well, I've sanded both epoxy with wood flour and the fairing mix of microballons and silica. The fairing mix might sand a bit easier compared to the wood flour but it's not that great of a difference in my opinion. It still gets hard.

The biggest difference I've noticed is the fairing mix goes on much more smoothly and after sanding there's more small pinholes or tiny voids in the wood flour mix compared to the fairing mix.
Eric (aka, piperdown)

"Give an Irishman lager for a month and he's a dead man. An Irishman's stomach is lined with copper, and the beer corrodes it. But whiskey polishes the copper and is the saving of him." --> Mark Twain

Aripeka Angler
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 6007
Joined: Thu Sep 13, 2007 9:13 pm
Location: Dade City, Florida

Re: Fairing mixture.

Post by Aripeka Angler » Wed Jun 05, 2019 7:02 pm

OrangeQuest wrote:
Wed Jun 05, 2019 8:31 am
Just ordered the micro balloons to mix with epoxy for my fairing tasks that are coming up. Is it ok for me to use wood flour in with it when I need to stiffen it up for vertical applications? I have plenty of wood flour but no silica.

Reminding that I am on a very tight budget! 8O
Control the sag on vertical fairing applications with a slightly stiffer mix of blended filler and epoxy.
Since you are on a tight budget, you can save some money by not troweling on thick coats of fairing compound. With thin coats, you will reduce runs and you’ll do better work. I find I usually end up sanding off and wasting most of a sloppy, thick coat of fairing.
Forget the wood flour as an additive to final fairing compound. WF works good as a scratch fairing coat on a rough surface or deep defect but it’s not really much good in a quality final fairing mix.
Richard
Completed boats...XF20 "Red Alert", Aripeka Angler's Strip Canoe, FS18 “Bare Bones”, GF12
Currently building...PY12 Kayak
If there is magic on this planet, it is contained in water. - Loren Eiseley

Dutch1
Active Poster
Active Poster
Posts: 401
Joined: Sun Mar 06, 2016 2:08 am
Location: Tallahassee, FL

Re: Fairing mixture.

Post by Dutch1 » Wed Jun 05, 2019 7:46 pm

Some really good advice from these posts. I ran my fairing mix through a small blender I got at goodwill and it made it a lot smoother to work and I didn't have the big chunks of mix to try and break up. I read about it on someones thread here and it really works well.

And, yes, you can add wood flour but as they said it will be a little harder to sand and will more than likely have pin holes that you have to deal with. The final fairing mix is supposed to be easy to work with, sand, and shape to the final shape you want.

User avatar
Capt UB
* Bateau Builder *
* Bateau Builder *
Posts: 2741
Joined: Mon Jan 03, 2011 7:12 pm
Location: DeLand, Florida
Location: Central Florida USA

Re: Fairing mixture.

Post by Capt UB » Wed Jun 05, 2019 7:50 pm

I used wood flour to fill in the weave and fill larger low spots. The mix works fine for me. I want the first coat of fairing to be hard without the soft additives. I put it on with a long straight edge.

I do and will allways finish with QuickFair. To me Quickfair is like a high build primer.
><((((º>¸.•´¯`•><((((º> ¸.•´¯`•.¸¸><((((º> ¸.•´¯`•.><((((º>

User avatar
OrangeQuest
Very Active Poster
Very Active Poster
Posts: 2352
Joined: Tue Aug 28, 2018 1:14 pm
Location: Houston, Texas

Re: Fairing mixture.

Post by OrangeQuest » Wed Jun 05, 2019 9:02 pm

Thanks for all the input from everyone!
The blender idea sounds pretty good, I have a single speed that only hold 16 ounces. Here in Texas that's not even big enough for a cup of coffee! The pin holes and the roughness has me concerned. I have been using wood flour mix to build up gaps and then sanding them back down to be even with the areas around them. I was thinking fairing is for filling in edges and areas that primer just doesn't hide. The glass I laid on the inside sides still needs the threads knocked down but most of that will happen after I get the sole taped and glassed in. The area the fillets and tape goes will get rough sanded but not enough to be smooth, just no air traps, the tape will cover that area up. I am guessing after I feather the tape and glass into the sides I will then continue to sand and fair the weave away on the sides. Then glue in the side ribs/frames. Or should I glue in the ribs then sand and fair in all the little spaces? :doh:

I was thinking like Capt UB stated, using the fairing mix as a high build primer. I posted an article of how a airplane builder got pinholes out of his wings, I may try his method. I picked up some big plastic spreaders from HD to get the mix spread evenly across large flat areas like the sole but the mix needs to be thin to work with them.
"that it isn't just an ordinary sort of boat. Sometimes it's a Boat, and sometimes it's more of an Accident. It all depends." "Depends on what?" "On whether I'm on the top of it or underneath it."
A. A. Milne

seaslug
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 654
Joined: Sat Nov 28, 2015 8:10 pm
Location: florida

Re: Fairing mixture.

Post by seaslug » Wed Jun 05, 2019 10:09 pm

I've never had much of a problem with pinholes using just micro balloons, or with a little silica on vertical areas to prevent sagging. The small amount of pin holes are easy enough to fill in later before priming. I find the best way to get and even fairing thickness is to spread the filler on with a notched spreader, than quickly pull a wide flat spreader across to flatten the notches. Same concept as laying tile using a notched trowel for thin set. I waste very little material this way, by paying close attention to film thickness, and working slow and methodical at this crucial stage. Anything to avoid too much sanding. Mike

Post Reply

Who is online

Users browsing this forum: No registered users and 28 guests