Glass over filler

I have been working on my skirts the aft end is built up with filler to make it nice a smooth. I am ready to prime but then I had a thought, do I need to lay a layer of glass over the top here. The stock skirt is in under this filler, which is a combination of West system 407 filler (base) and 410 filler the lighter stuff. the white stuff is Evercoat filler, it said on the can it will not shrink, it fills some shallow low areas.

Do do I
1. lay cloth over this
2. Just a couple coats of clear epoxy or
3. Just paint epoxy primer over the filler.

I have already put on a couple coats of clear epoxy but I did another layer of 410 and in sanding the last coat I broke though in some places. Not sure how durable the epoxy primer is compared to a coat of clear epoxy.

Thanks.

I just ordered some evercoat Rage to check it out myself. no intending to hijack, just would like to know the answer myself

Seeing as you already had clear epoxy on it, I would recoat the areas you sanded through, and sand lightly again.

This will give you a uniform base for the primer to work on.

You do not need glass cloth over filler.

The filler may need an epoxy wipe (with a squeegee, not a brush) if it shows exposed pinholes, usually tiny air bubbles cut open when sanding.

I have no idea why anyone would place polyester filler over epoxy/micro.

No Patients

I had this small area that was not to the smooth shape I wanted, there was a very shallow low spot. I did not want to wait a day and I found this Evercoat stuff (Formula 27) that claims it does not shrink. Keep in mind I am very new to this stuff and I am leaning a lot, in part to you and others on this site.

So based on what you posted should I sand off the Evercoat and go back and apply micro?

Cheers

DanH said:

You do not need glass cloth over filler.

The filler may need an epoxy wipe (with a squeegee, not a brush) if it shows exposed pinholes, usually tiny air bubbles cut open when sanding.

I have no idea why anyone would place polyester filler over epoxy/micro.

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Mike,

I'am using micro and cabosil mixture to fill in on my skirt. I also am new to glass work. I know builders around here are using rage gold over epoxy without any ill effects but I have micro and cabosil on hand so I mix up a slurry and wait until morning then block it back off.

From Evercoat, specific to Formula 27 and others:

Note: Polyester Fillers cannot be used over epoxy resin repair areas. These fillers will not adhere to epoxy surfaces.

and

PROBLEM: Filler did not adhere properly to surface, broke away, or popped off.

CAUSES: Surface applied to was not prepared properly, or was made of material the filler could not bond to, or the filler was applied too thick.....Fillers will not achieve a good bonding on some surfaces such as sheet molded compound (SMC), epoxy, fiberglass, aluminum or galvanized steel. Specialized fillers or resins must be used on those surfaces.

Source:

http://www.evercoat.com/imgs/pis/Polyester Filler Final.pdf

Wow so much to learn

Dan thank you for pointing this out to me, I guess I was confused when the list of materials it could be used for included fiberglass, I guess that means glass in polyester resin.

One question though, did you not say that you will use a polyester product to fix small blemishes, I am guessing smaller than what was in my photo. Is there not a concern of separation due to the epoxy primer that goes over the top?

There is just no good place to get information on what is compatible with what. Thanks again, as always you are a wealth of knowledge.

OK now what should I do, today I went ahead and applied a coat of clear epoxy and it looks like I will get darn near all the holes, it is flowing out to be nice and smooth. I did however apply this over the Evercoat area. Should I sand this off now or see how it hold up since I will paint after flying and more finish work will be done on the plane? I am looking for advice, and of course how you would handle this. Or anyone else in the know.

Cheers

DanH said:

From Evercoat, specific to Formula 27 and others:

Note: Polyester Fillers cannot be used over epoxy resin repair areas. These fillers will not adhere to epoxy surfaces.

and

PROBLEM: Filler did not adhere properly to surface, broke away, or popped off.

CAUSES: Surface applied to was not prepared properly, or was made of material the filler could not bond to, or the filler was applied too thick.....Fillers will not achieve a good bonding on some surfaces such as sheet molded compound (SMC), epoxy, fiberglass, aluminum or galvanized steel. Specialized fillers or resins must be used on those surfaces.

Source:

http://www.evercoat.com/imgs/pis/Polyester Filler Final.pdf

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RVG8tor said:

One question though, did you not say that you will use a polyester product to fix small blemishes, I am guessing smaller than what was in my photo.

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Smaller indeed. I wipe polyester putty into a pinhole as a quick fix, if I find one or two after spraying an epoxy primer check coat. Then I sand off everything except the material remaining down in the pinhole.

There is just no good place to get information on what is compatible with what.

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It's been discussed here more than once, and that Evercoat document turns up in the first page of a Google search.

OK now what should I do......

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You know the facts. It's your airplane.

OK

Go it thanks

DanH said:

Smaller indeed. I wipe polyester putty into a pinhole as a quick fix, if I find one or two after spraying an epoxy primer check coat. Then I sand off everything except the material remaining down in the pinhole.



It's been discussed here more than once, and that Evercoat document turns up in the first page of a Google search.



You know the facts. It's your airplane.

Click to expand...