Between Coats of Fairing

See our FAQ and tutorials before posting.
Post Reply
Dan_Smullen
Active Poster
Active Poster
Posts: 237
Joined: Tue Aug 13, 2019 3:02 pm
Location: VA

Between Coats of Fairing

Post by Dan_Smullen » Sat Jan 04, 2020 9:02 am

I've been spreading thin layers of blended microballoons and glass spheres, screeding into low areas adjacent to seams, then sanding with a longboard.

Seems to be yielding good results. Haven't got into Quick Fair yet. Have some ordered, and will use for final passes.

I'm wiping down with warm water and letting it dry before spreading the next layer, after sanding.

Should I be wiping down with something harder like alcohol? Should I be rolling neat epoxy before spreading fairing compound?
5965



terrulian
* Bateau Builder *
* Bateau Builder *
Posts: 2816
Joined: Sat Dec 07, 2013 11:29 am
Location: Marin County, CA
Contact:

Re: Between Coats of Fairing

Post by terrulian » Sat Jan 04, 2020 9:49 am

All surfaces should have been saturated with neat epoxy before fairing. Otherwise I don't see the argument for neat epoxy, say between fairing layers, as it is harder to sand.
Jacques likes lacquer thinner for a wipe-down as I think he believes it contains fewer contaminants. I've used water, acetone, and alcohol. I haven't seen much difference, but I'm an idiot.
Tony
Image

fallguy1000
Very Active Poster
Very Active Poster
Posts: 4572
Joined: Tue Jan 12, 2010 12:25 am

Re: Between Coats of Fairing

Post by fallguy1000 » Sat Jan 04, 2020 9:52 am

Dan_Smullen wrote:
Sat Jan 04, 2020 9:02 am
I've been spreading thin layers of blended microballoons and glass spheres, screeding into low areas adjacent to seams, then sanding with a longboard.

Seems to be yielding good results. Haven't got into Quick Fair yet. Have some ordered, and will use for final passes.

I'm wiping down with warm water and letting it dry before spreading the next layer, after sanding.

Should I be wiping down with something harder like alcohol? Should I be rolling neat epoxy before spreading fairing compound?
5965
Decent questions... I like to use alcohol to wipe, but water is okay; just dries slower. Sometimes the alcohol flashes so fast, it is ineffective and water can be better unless you are worried about water deposits..

You can't fair if you roll neat epoxy, so no. However, you really need to make sure to either have key for fairing compounds or be within the recoat windows or both. I don't like fairing over shiny surfaces.
My boat build is here -------->

viewtopic.php?f=12&t=62495

Dan_Smullen
Active Poster
Active Poster
Posts: 237
Joined: Tue Aug 13, 2019 3:02 pm
Location: VA

Re: Between Coats of Fairing

Post by Dan_Smullen » Sat Jan 04, 2020 9:58 am

I’m going to say I have good epoxy coverage prior to fairing. Epoxy was squeegeed over fabric to the point that now cured, I can feel the weave. Then I scuff sanded with 60 grit on an orbital. Then wiped with alcohol.

Bite feels good, and sanding is yielding good results. I was worried about layers biting into previous layers.

Thanks, gents. Keep building!

joe2700
Active Poster
Active Poster
Posts: 365
Joined: Fri Nov 25, 2016 3:16 pm
Location: Massachusetts

Re: Between Coats of Fairing

Post by joe2700 » Sat Jan 04, 2020 11:19 am

terrulian wrote:
Sat Jan 04, 2020 9:49 am
All surfaces should have been saturated with neat epoxy before fairing.
Why do you say that? I think it only applies to bare wood, maybe that's what you meant. I don't see any reason to have a layer of neat epoxy between saturated cloth and fairing compound. It won't add strength and saturated cloth is already waterproof. I see an argument for neat epoxy over the last coat of fairing compound, as sanding will have opened the top layer of micro balloons/glass spheres. I personally don't, since neat epoxy will mess up my "perfect" faired surface with a hard to sand uneven layer, and I trust the epoxy primer to seal it up. You should do whatever your fairing compound and primer calls for. System 3 yacht primer can be applied directly over system 3 quick fair.

terrulian
* Bateau Builder *
* Bateau Builder *
Posts: 2816
Joined: Sat Dec 07, 2013 11:29 am
Location: Marin County, CA
Contact:

Re: Between Coats of Fairing

Post by terrulian » Sat Jan 04, 2020 11:25 am

Right, bare wood was what I meant. If you've already glassed a surface, it has been saturated with epoxy.
Tony
Image

Dan_Smullen
Active Poster
Active Poster
Posts: 237
Joined: Tue Aug 13, 2019 3:02 pm
Location: VA

Re: Between Coats of Fairing

Post by Dan_Smullen » Sat Jan 04, 2020 11:59 am

terrulian wrote:
Sat Jan 04, 2020 11:25 am
Right, bare wood was what I meant. If you've already glassed a surface, it has been saturated with epoxy.
10-4.

Post Reply

Who is online

Users browsing this forum: No registered users and 32 guests