Taping for graphite

[jbo_c]

I’m close to ready to graphite the bottom of my hull. Do y’all have any favorite tapes for masking? Are any of them problematic with the epoxy? I’m a little paranoid about some seeping/running under and botching a clean edge.

I have Scotch brand original(#2090). Good? I’m betting in this instance, you probably do get what you pay for, so don’t mind getting something else if it’ll work appreciably better.

Also, I’m assuming if you do multiple coats in immediate succession, you just leave the tape in place until the last coat kicks and pull off before it fully cures. (?). Don’t want to epoxy the edge of the tape to my hull.

Jbo

[TomW1]

You need to remove the tape between the coats otherwise the first coat will have set up by the time you finish the last coat. The build up on the tape will make it very difficult to remove it also, you will need a razor knife to cut it free.

Tom

[fallguy1000]

Remove tape immediately after each coat or it'll be stuck almost perfectly and forever.

Heed Tom's wisdom on this one.

[jbo_c]

Just in case somebody looks at this at a future date:

I ended up painting on one coat of graphite, waiting 3 hours, painting on a second coat of graphite, waiting 90 minutes, then pulling the tape. First coat was still green and second coat was past sagging. It made a nice clean line and no issues with tape being “stuck” to the epoxy.

This was MarinEpoxy with slow hardener applied in mid-80s temperatures.

Jbo

[Jaysen]

I didn’t mention this earlier but I tend to cheat this.

I put down multiple tape layers with a 1/16” or so offset. First tape right in the desired line. Second layer 1/16 inside. Third layer 2/16” inside the line. Add layer and a 1/16” for each planned layer.

Problems:
1. You have to do all the layers or you’ll have and odd step…
2. You have nice feather to sand out now. If you’re lazy jaysen you tape the opposite way and just paint it smooth.
3. If you’re lazy jaysen and not painting it smooth it’s easy to over sand the tape ridges and make a mess.

I’ve used this trick for paint as well. Seems to work well for me.

[BarraMan]

I, on the other hand, just rolled multiple layers up to a sharp edge (strake/chine) with no masking!

[wpstarling]

so i just used a single layer of blue painters tape and did all my layers (4 in total) and then removed the tape with no issues whatsoever. I would do 1 coat of graphite, wait about 30-45 minutes (depending on temperature) and then do the next layer of graphite. I have a nice crisp line. When I did the primer and paint above the graphite I taped right at the graphite line and you can barely feel a difference. Now if you want show quality then do the overlapping layers for a smooth transition