MarinEpoxy (fast) recoat window

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VT_Jeff
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MarinEpoxy (fast) recoat window

Post by VT_Jeff »

Does someone know what the max wet-on-wet recoat window is with the marinepoxy fast? I'd like to avoid washing blush/sanding whenever possible.

Thanks,

Jeff
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OneWayTraffic
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Re: MarinEpoxy (fast) recoat window

Post by OneWayTraffic »

For all epoxies it depends on Temperature. A 10 degree C change (about 18F) will half cure times. Generally, if it's still slightly tacky or you can dig a thumbnail into it it's fine. I can't talk specifically about Marinepoxy though.

Reid
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Re: MarinEpoxy (fast) recoat window

Post by Reid »

Like OneWay said, it depends on temp. If you are doing some bright finish work I would wait until it is cured, wipe off any blush, sand, and recoat. If you are laying up glass or laminating then you simply need to wait till after the initial kick. Once it has set up enough to where the first layer of glass won't slide on you, you can probably continue with the next layer. This is more of a "green on wet".
For true "wet on wet" you simply add the next layer as soon as the first one is down. The risk you take is having all that heat build up between the layers and the lamination kicking off really fast and cutting down dramatically on your work time.

Hope this helps,
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VT_Jeff
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Re: MarinEpoxy (fast) recoat window

Post by VT_Jeff »

Reid wrote: Thu Dec 17, 2020 2:40 pm If you are laying up glass or laminating then you simply need to wait till after the initial kick. Once it has set up enough to where the first layer of glass won't slide on you, you can probably continue with the next layer.
Hope this helps,
-Reid
Thanks Reid.

That makes sense, but I'm more wondering about the other side of the window, the max time I can wait before re-coating without the need to wash/sand; Can I wet out glass in the morning, work a full day and then add a coat after work(I work at home)? temps in the basement are 50's/low 60's, I can get it cooler with no problem.

edit: Silvertip advertised 72 hours, by comparison
There are only two seasons in Vermont: boating season, and boat-building season.

Completed Paul Butler 14' Clark Fork Drifter
Completed Jacques Mertens FS14LS + 10%, Build Thread
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Reid
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Re: MarinEpoxy (fast) recoat window

Post by Reid »

VT_Jeff wrote: Thu Dec 17, 2020 2:45 pm
Reid wrote: Thu Dec 17, 2020 2:40 pm If you are laying up glass or laminating then you simply need to wait till after the initial kick. Once it has set up enough to where the first layer of glass won't slide on you, you can probably continue with the next layer.
Hope this helps,
-Reid
Thanks Reid.

That makes sense, but I'm more wondering about the other side of the window, the max time I can wait before re-coating without the need to wash/sand; Can I wet out glass in the morning, work a full day and then add a coat after work(I work at home)? temps in the basement are 50's/low 60's, I can get it cooler with no problem.
I don't have a solid answer for you. Unfortunately blushing depends on several factors, the primary ones being temperature and humidity. The only real way to tell is to do a test. I am down here in FL and very rarely use anything but slow hardener. Our Slow MarinEpoxy doesn't blush so I can do a lamination and come back 12 hours later some times and do another layer without sanding in between. However, I can only do this because I am not contending with a possible blush.
I will say this, people tend to way overthink the blush. If it happens to blush just wipe down with warm soap and water or a solvent and keep building. If you are ready to add the next layer just run a gloved finger over your first lamination, if it is oily or greasy then it blushed, it not then go forward with the next layer.

-Reid
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fallguy1000
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Re: MarinEpoxy (fast) recoat window

Post by fallguy1000 »

With cooler temps; you will need to do the greasy surface check for amine blush.

No reason same day and overnite won't be workable no sanding, but watch out for the blush.
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VT_Jeff
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Re: MarinEpoxy (fast) recoat window

Post by VT_Jeff »

Reid wrote: Thu Dec 17, 2020 2:57 pm
VT_Jeff wrote: Thu Dec 17, 2020 2:45 pm
Reid wrote: Thu Dec 17, 2020 2:40 pm If you are laying up glass or laminating then you simply need to wait till after the initial kick. Once it has set up enough to where the first layer of glass won't slide on you, you can probably continue with the next layer.
Hope this helps,
-Reid
Thanks Reid.

That makes sense, but I'm more wondering about the other side of the window, the max time I can wait before re-coating without the need to wash/sand; Can I wet out glass in the morning, work a full day and then add a coat after work(I work at home)? temps in the basement are 50's/low 60's, I can get it cooler with no problem.
I don't have a solid answer for you. Unfortunately blushing depends on several factors, the primary ones being temperature and humidity. The only real way to tell is to do a test. I am down here in FL and very rarely use anything but slow hardener. Our Slow MarinEpoxy doesn't blush so I can do a lamination and come back 12 hours later some times and do another layer without sanding in between. However, I can only do this because I am not contending with a possible blush.
I will say this, people tend to way overthink the blush. If it happens to blush just wipe down with warm soap and water or a solvent and keep building. If you are ready to add the next layer just run a gloved finger over your first lamination, if it is oily or greasy then it blushed, it not then go forward with the next layer.

-Reid
Gotcha, appreciate it!
There are only two seasons in Vermont: boating season, and boat-building season.

Completed Paul Butler 14' Clark Fork Drifter
Completed Jacques Mertens FS14LS + 10%, Build Thread
Started Iain Oughtred Tammie Norrie

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VT_Jeff
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Re: MarinEpoxy (fast) recoat window

Post by VT_Jeff »

fallguy1000 wrote: Thu Dec 17, 2020 3:14 pm With cooler temps; you will need to do the greasy surface check for amine blush.

No reason same day and overnite won't be workable no sanding, but watch out for the blush.
Ok, thanks Dan!
There are only two seasons in Vermont: boating season, and boat-building season.

Completed Paul Butler 14' Clark Fork Drifter
Completed Jacques Mertens FS14LS + 10%, Build Thread
Started Iain Oughtred Tammie Norrie

OneWayTraffic
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Re: MarinEpoxy (fast) recoat window

Post by OneWayTraffic »

I often put epoxy on in the evening then coat the next day without sanding. I always do it early before it warms up. After a day, I'll use a scotchbrite and a bucket of water. This cleans and scuffs. Then dry it and go. Or if I'm pretty sure that there's no blush I'll just sand and go. That works as well. I'm using WEST; the Gougens used to recommend washing only if there was visible evidence of blush, now they recommend it regardless.

On a technical level the cure goes on for a day or two typically after the epoxy has dried. Sometimes much longer: if the temperature is marginal it might never reach 100%. But contaminants build up on the surface, and your next coat will be bonding to this rather than the surface. Abrasion removes contamination, and increases the surface energy so your epoxy will flow into it. It never hurts to give a little rough up even if you are pretty sure that the primary bond is ok.

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