Narfi's HC14 build thread - LAUNCHED

[gonandkarl]

Hi,
I used on my FS13 and on the AD14 a ratio of one third of mixed resin in weight like when I made 155 grams of mixed resin I put in 55 grams of graphite powder. Seeing that you have problems with the temperature up there in Alaska try to do it on the hottest day still coming and mix epoxy and graphite inside the house where you got it for sure warmer. As Cracker Larry once said you cannot mix hot chocolate powder in cold milk the same goes for graphite powder in epoxy. Maybe someone on the forum can give you advise how to warm epoxy. Good luck with the graphite application.
Greetings from Karl

[narfi]

Thanks Karl.
Do you know what that ratio would be by volume?

Temps are a concern.
I was planning on heating the epoxy in hot water before mixing then going over the surface with a hot air gun right after application.... air temp probably 60-70f

[Fuzz]

I think you might want to add some form of heat to the shop. It is looking like the next warm day will be in 2018

[Eric1]

Narfi, I've been doing my graphite with morning temps around 70-72. It really rolls fine at that temp. I am counting on it to warm up through the day to cure overnight. We have been 88-91 degrees in the afternoon. I can understand you warming your epoxy and I agree with Fuzz about warming the shop too. Best of luck!

[narfi]

I sanded the excess glue around the compartment tops and got them smooth and flush with the rub rails.

Then I used the router to round over the rub rails in and out. Pictures don't do it justice, I am really happy with the fully rounded over tops.

Glasses the outside of the compartments tops and bulkheads with 4oz. Then put the first epoxy coat over all the bare wood on the rub rails.

If weather doesn't change I am probably going to have to take it to work and paint it.... still thinking about heating options for the tent :/

[Fuzz]

I keep my shop at 60f when glassing. The epoxy has always been good to go after sitting over night.

[gonandkarl]

Unfortunately I do not know the graphite epoxy ratio by volume but I can try to guess from what I remember when I mixed it in a small yoghurt plastic cup.
I think it was about the same volume as the mixed resin. 6 ounces of mixed resin with roughly 15 small plastic spoons full of graphite powder. Full means to scoop it up with the spoon and because the graphite powder is so fine that there will be no heap on the spoon because it runs off its side the same as micro balloons. Hopefully this will help you.

[cape man]

I used 25% graphite by volume.

[narfi]

Got up this morning and put a layer of fairing compound over the fresh glass.
My Bondo scrapers aren't as smooth as when I started the project..... starting to leave grooves....... Will want to buy extras when I start the big boat.
Put a second coat of epoxy on the rubrail and used left over fairing compound to fill a couple small voids.

When you say 25% do you mean 25% of the epoxy? (4parts epoxy 1 part graphite) or do you mean 25% of the total? (3 parts epoxy 1 part graphite)

Either way the difference between your ratio and Karl's 50/50 is significantly different..... what are the advantages and disadvantages to going heavy on graphite or light on graphite in the mix?

[cape man]

1/4 graphite, 3/4 epoxy. Don't know advantages over that and Karl's recipe, but that's what the Cracker told me to use. Sift the graphite and add the epoxy to it while stirring much like making a batter. 8 years later it's still slick and hard as ...well graphite, mixed with epoxy.