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Empennage Fairing

wirejock said:
Micro thinned 5% with denatured alcohol. It's thinned enough to spread and the solvent flashes off before it starts to flow. A few drips. I rotated it every few minutes to keep from getting pools of micro.
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Why thinned 5%?
 
wirejock said:
Because I can mix more micro into a thinner mix. It goes on smoother. It gets thicker quickly because the alcohol flashes off. It sands easier and faster.
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And what does you epoxy manufacturer have to say about thinning?

Here's what West has to say.

Thinning West Epoxy.jpg

I can't support thinning epoxy in the homebuilder's world. If we are to claim it doesn't reduce mechanical properties, then why not thin epoxy in laminate layups? After all, wouldn't it make wet-out faster and easier?

The concept of ad hoc epoxy chemistry in homebuilding just flat scares the spit out of me. Be a leader. Don't encourage it.
 
DanH said:
And what does you epoxy manufacturer have to say about thinning?

Here's what West has to say.

View attachment 55025

I can't support thinning epoxy in the homebuilder's world. If we are to claim it doesn't reduce mechanical properties, then why not thin epoxy in laminate layups? After all, wouldn't it make wet-out faster and easier?

The concept of ad hoc epoxy chemistry in homebuilding just flat scares the spit out of me. Be a leader. Don't encourage it.
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Yes sir.
 
Stoo said:
Best way to thin epoxy ( with or without micro) is to work with a squeegee in one hand and a heat gun in the other.
Stewart Willoughby, 6
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My methods are not new. If you search for threads related to thinning epoxy, there are a few with more % dilution. To be fair, I only suggested thinning it for micro. If it departs, it will take some paint off. Please ignore the comment or moderators feel free to delete it.
 
There's a lot of time and effort involved in finishing the emp fairing, for what looks like a small part. Here's a pic of mine, this is after micro and sanding and two coats of epoxy primer with sanding in between. It needs another coat of epoxy primer and then more sanding. The West System free tech guides on their website are good and I used their method of applying micro, which is to brush on a thin coat of epoxy first before icing (or is that frosting?) the cake.


20240130_083145.jpg
 
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Sorry to bring it up again Larry but Dan your approach here while warranted in many applications (structural) doesn't seem as doom and gloom to me in this application. Maybe I missed something... Something tells me that that fairing could spontaneously disintegrate and the plane would still fly. Build on Larry, no reason to delete anything in my opinion. I would fly with you! :)
 
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jcarne said:
Sorry to bring it up again Larry but Dan your approach here while warranted in many applications (structural) doesn't seem as doom and gloom to me in this application.
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A non-critical application doesn't justify a bad practice, in particular when it has no practical value.
 
DanH said:
A non-critical application doesn't justify a bad practice, in particular when it has no practical value.
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What exactly is the "bad practice", is it "thinning", or is it thinning with the "wrong" thinner? The official Van's construction manual advises us to thin epoxy with 50% acetone when sealing the cowl, so is that considered a "sin"? If so then Van's Aircraft Inc is leading us to sin!
 
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PaulvS said:
What exactly is the "bad practice", is it "thinning", or is it thinning with the "wrong" thinner? The official Van's construction manual advises us to thin epoxy with 50% acetone when sealing the cowl, so is that considered a "sin"? If so then Van's Aircraft Inc is leading us to sin!
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Thinning with anything.

Eve was a nice lady, but there was this one time....
 
vlittle said:
I fabricated elevator closeouts like this:

View attachment 55003

View attachment 55002
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Looks nice.
The inboard elevator caps I employed on Race 57 were more like miniature wing tip fairings, not flat as pictured above, but tapered to hopefully help blend the turbulent air flow trailing thru there. They filled as much gap between elevator & rudder without interfering their movement. Sorry, no pictures, would explain much better.
 
DanH said:
Thinning with anything.

Eve was a nice lady, but there was this one time....
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Not to pick on DanH but I do not have a problem thinning Polyester Filler with Polyester resin.

Like DanH, I do not think Epoxy should be thinned with anything.

Since this thread was about Epoxy, I will say sorry for the thread drift.
 
Scout48 said:
Sorry to hear that you shut down your blog. I found it to be very helpful.
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It's not technically shut down. It's my builder log. It's still current. It's just no longer public. I do not want the liability exposure. If someone wants access and agrees to the disclaimer, I will allow it. Send me an e-mail if you want access.
Wirejock at yahoo dot com
 
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