Sharpie and epoxy?

SolarYellow

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I'm going to use black G10 for fins on a small rocket. Plan is to leave them black and not paint them, saving time, work, weight, thickness, etc. BSI 30-minute epoxy to attach the G10 to the cardboard. Because I won't run the BT finish color all the way up the fillet, there's potential for a gap alongside the fin, in the fillet, where the BT color shows through. I'm thinking just Sharpie the BT black around the fins so the fillet is clear epoxy over black G10 and black BT. Should look fine.

Any chance of the Sharpie black leaving something in the cardboard that limits adhesion or affects curing of the epoxy? Obviously, I'll wait a few hours at least so all the solvents evaporate.
 

DeltaVee

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I'm going to use black G10 for fins on a small rocket. Plan is to leave them black and not paint them, saving time, work, weight, thickness, etc. BSI 30-minute epoxy to attach the G10 to the cardboard. Because I won't run the BT finish color all the way up the fillet, there's potential for a gap alongside the fin, in the fillet, where the BT color shows through. I'm thinking just Sharpie the BT black around the fins so the fillet is clear epoxy over black G10 and black BT. Should look fine.

Any chance of the Sharpie black leaving something in the cardboard that limits adhesion or affects curing of the epoxy? Obviously, I'll wait a few hours at least so all the solvents evaporate.
Good question. Don't know the answer unfortunately. You could try using the sharpie on some card board pieces and the glue them together. Also have some non-sharpie pieces and glue them together as a control... see if you can detect a difference perhaps. I'm inclined to agree with @PayLoad but I just don't know. Of course there are black pigments you can add to the epoxy...
 

pathtouch

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Could you add a drop of black pigment to the epoxy? I’ve used the cheap Amazon stuff and am happy with the results. Completely opaque on my current build, I am also trying to avoid painting my fin can.
 

jqavins

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  • Sharpie plus epoxy:
    • Probably no problem for the epoxy (say others I have no reason to disbelieve).
    • Potential problem for the sharpie. I strongly urge a little test piece.
  • Epoxy plus clearcoat: (just in case you're thinking of using clearcoat) obviously no problem, people do it all the time.
  • Sharpie plus clearcoat: Problem. I tried it once where some decals fell a little short so extended black bands by hand. Clear coat has lots more solvent than many other rattle cans. The sharpie ran, and ran real bad.
  • No clear coat, no problem.
 

tsmith1315

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One more: Epoxy plus pigment, no problem.

I've used food coloring, inks and alcohol dyes. If there's a bottle nearby, I always add it in. If nothing else, it helps to be sure you mix it thoroughly.
 

jqavins

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One more: Epoxy plus pigment, no problem.

I've used food coloring, inks and alcohol dyes. If there's a bottle nearby, I always add it in. If nothing else, it helps to be sure you mix it thoroughly.
What would you use for black? I'm thinking of air float charcoal (which some of happen to have on hand for, um, other purposes).
 

tsmith1315

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What would you use for black? I'm thinking of air float charcoal (which some of happen to have on hand for, um, other purposes).

;)

Lamp black, epoxy dye, black ink, the ink/dye can look purple if not a thick enough later, especially cheap stuff.

Seems like I tried tempura powder way back when. I don't remember the outcome, maybe it was too traumatic.
 

prfesser

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What would you use for black? I'm thinking of air float charcoal (which some of happen to have on hand for, um, other purposes).
I have about half a pound of lampblack, and a couple pounds of thermax (somewhat coarser, denser carbon black). I'll post details in the For Sale section a bit later today, but it'll be free, recipient pays only actual postage.

Lampblack is the pigment used in so-called India ink. Extremely fine, great for staining hands, clothing, floors, walls, pets, people, many other items.

Best,
Terry
 

hobie1dog

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I use a black epoxy from Global Adhesives.
kQLs41B.jpg
 

lakeroadster

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  • Sharpie plus clearcoat: Problem. I tried it once where some decals fell a little short so extended black bands by hand. Clear coat has lots more solvent than many other rattle cans. The sharpie ran, and ran real bad.

A definitive case of YMMV

I read here on TRF that this was an issue. I used red Sharpie brand marker on my Thunk! rocket to free hand its name. When I clear coated the rocket, I put a very light coat of Rustoleum 2X Clear over the Sharpie'd letters only, and let it dry for an hour. Then I applied the second coat. Neither coat changed the Sharpie in any way whatsoever.

My plan was to seal the Sharpie with the light coat to minimize the solvent issues.

Might have something to do with the brand of clear coat being used and how heavy it is applied? :dontknow:

001.JPG 002.JPG
 
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jqavins

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I guess "YMMV" should be considered implied in any post such as I wrote unless specified otherwise. I don't remember what brand of clear I was using, and for that matter I don't know if it was literally a Sharpie brand marker. So, let me rephrase:

CAUTION: the application of clearcoat (brand and product line unspecified) applied over permanent marker inks (brand and product line unspecified, often referred to informally as "sharpie" or "magic marker") presents a risk of causing the ink to run, the degree of said running potentially being severe.

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