Scraping and thinning epoxy?

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piperdown
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Scraping and thinning epoxy?

Post by piperdown »

So I've been watching Lou on his channel building a skiff. https://www.youtube.com/watch?v=SqiU8OXgTVA

2 things that jumped out at me. 1 was using a scrapper and 2 was thinning the epoxy with denatured alcohol.

Has anyone else done this?

Based on what he said in the video he's done this with lots of boats over the years.
Eric (aka, piperdown)

"Give an Irishman lager for a month and he's a dead man. An Irishman's stomach is lined with copper, and the beer corrodes it. But whiskey polishes the copper and is the saving of him." --> Mark Twain

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VT_Jeff
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Re: Scraping and thinning epoxy?

Post by VT_Jeff »

piperdown wrote: Tue Mar 30, 2021 10:55 am So I've been watching Lou on his channel building a skiff. https://www.youtube.com/watch?v=SqiU8OXgTVA

2 things that jumped out at me. 1 was using a scrapper and 2 was thinning the epoxy with denatured alcohol.

Has anyone else done this?

Based on what he said in the video he's done this with lots of boats over the years.
Great find Eric!

Scraping the stitching seems genius, I'll have to try that.

I have not thinned with spirits, this article convinced me to thin by heat instead of alcohol etc.
https://www.epoxyworks.com/index.php/th ... tem-epoxy/

But I am a strong believer in "If it works for you, do it" and Lou certainly knows what works for him.
There are only two seasons in Vermont: boating season, and boat-building season.

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Re: Scraping and thinning epoxy?

Post by bklake »

The only scraper that worked for me was a carbide scraper. It works so well, it's almost as good as (fill in the blank). Seriously.

Has to be carbide. Flat surfaces only. Curves and corners get eaten up. 3 seconds to take care of a drip.

Never thinned epoxy. I'm not one to mess with the delicate chemistry involved.

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Re: Scraping and thinning epoxy?

Post by Fuzz »

I would be very careful about thinning epoxy. If you want to do it I would do some experimentation first.
I have seen his videos. He is not using glass and epoxy for strength the way stitch and glue does.

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Re: Scraping and thinning epoxy?

Post by mattkab »

According to this video, it helps saturate the cloth (which I don't know that I'd do), but also helps self-level (which I'm interested in).

A quick google search says that acetone and denatured alcohol are both "safe" to thin epoxy up to 10%. I may experiment with it in some lockers of my GV-13 -- working in the PNW, temperatures won't consistently break 70 for a few more months, so I'm always fighting temperatures just to reach a syrup consistency, and I'm about to start the fairing process on the inside of the hull.
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joe2700
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Re: Scraping and thinning epoxy?

Post by joe2700 »

I find a steel cabinet scraper also works for epoxy.

Love Lou but I wouldn't thin epoxy unless the manufacture specified you can and how.

piperdown
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Re: Scraping and thinning epoxy?

Post by piperdown »

Don't get me wrong, I wouldn't thin epoxy down unless the manufacturer says it's okay. Plus I know Lou's boats aren't stitch and glue and don't really need the fg and epoxy to make them strong. I was curious about thinning epoxy and if others had done this.

One of the other things he did which made me go "I don't think that's a good idea" and I would never do on a S&G is spraying water on the wet fg to act as a lubricant to use a metal trowel to smooth the fg down.

I did come across a couple of articles that said thinning epoxy can cause a reduction in strength by up to 20%. It wouldn't seem to be an issue with how Lou constructs his boats but would be a large issue with S&G with JM's designs.
Eric (aka, piperdown)

"Give an Irishman lager for a month and he's a dead man. An Irishman's stomach is lined with copper, and the beer corrodes it. But whiskey polishes the copper and is the saving of him." --> Mark Twain

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Re: Scraping and thinning epoxy?

Post by cracked_ribs »

A scraper I use but to thin epoxy I use a heat gun. It gets very thin, and the wood gets nice and warm, and then cools down, pulling the epoxy further into the wood as the gases inside contract. Epoxying veneers, I can usually get it to soak right through from one side through 1/16 of wood and out the other side. I do it on wax paper so it doesn't glue itself down, that's how much glue I can get to soak through.
I designed my own boat. This is the build thread:

viewtopic.php?f=12&t=65349

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Re: Scraping and thinning epoxy?

Post by Dougster »

Linbide scraper for me (it's carbide). Fits my hand and gets rid of drips in a minute. I used it all the time on all builds.

https://www.ebay.com/itm/Linbide-Scrape ... SwtzJegu22

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Re: Scraping and thinning epoxy?

Post by Dan_Smullen »

I’m glad I’m not the only one who looks forward to the new Lou video dropping. :lol:

For a small project I once used Total Boat penetrating epoxy, and the directions said to thin with alcohol. I’ve since wondered about how MarinEpoxy would like it.

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