Thread: GIS Yawl

good stuff here chaps.

I generally don't fill the grain as a separate process - just rely on the coating to do it. I will sometimes use a bog mix to fill glass weave (if painting after of course) but I am suspicious it adds labour compared from just doing the filling.

For glassing and filling the weave - peel ply can be very nice if the panel and curve a good enough for it to sit down really flat - if it crinkles on the inside edge you just end up with more work compared to wet on wet application.

MIK

Ooooooh, good point on the peel ply. I have sweet dreams about releasing a nice peel ply surface....the lambs leaping over it...or cows...some farm animal...ah, GOATS!

Originally Posted by Boatmik

good stuff here chaps.

I generally don't fill the grain as a separate process - just rely on the coating to do it. I will sometimes use a bog mix to fill glass weave (if painting after of course) but I am suspicious it adds labour compared from just doing the filling.

For glassing and filling the weave - peel ply can be very nice if the panel and curve a good enough for it to sit down really flat - if it crinkles on the inside edge you just end up with more work compared to wet on wet application.

MIK

Hi Mick
I found oven paper does a great job at producing a really slick "no sand" surface too. Just lay it over the epoxy coat and give it a roll, removing air bubbles and leave it on until the epoxy goes off. Worked a treat on my foils, so am going to use in on the hull panels as well.

Does the oven paper (I call it parchment paper) release or do you just sand it off?

I ran an experiment a while back to see how well waxed Lexan worked for smoothing small areas like you get with the Payson butt splice method. The Lexan popped off very cleanly, leaving a glass-smooth surface.

When it came time to actually try it on a real butt splice I decided it might release easier if I did it while the epoxy was real firm but not yet fully cured. Big mistake! It seems epoxy sticks to waxed Lexan better than raw okoume until it goes fully hard. I ended up pulling about half the 'glass off. I was doing two joints so I let the other one fully cure and the Lexan popped off neatly.

My experience with parchment paper is that it does peel right off cured epoxy. Haven't tried removing it before the epoxy cured.

Mylar and other rigid plastics work well for this and it's a common method I employ. On compound curves, you can "diagonally plank" the sheet plastics to get a smooth finish. This is also an easy way to get a textured surface. Of course you need a textured plastic. I use a pebble finished piece of PVC, that I got from a home improvement store, it was used as a shower enclosure material, but now is my non-skid mold.

Never peel the "release" fabric before the goo has completely "gone off". You'll just make a mess and start cussing. I'm also hesitant about using anything on curing epoxy, that could contaminate the surface, like wax coatings.

I thought about the possibility of the wax contaminating the surface so I let the auto paste wax dry for a couple days then buffed it off. I'm hoping it was hard enough to stay put on the Lexan and not leave anything behind.

I had a couple butt splices to work today so I cut some parchment paper pieces then almost forgot to put them on. After the 'pox had been on for a half-hour or so I saw the paper sitting where I'd left it so I rolled it on. The temp is a cool 40 degrees F so the resin had not even started cooking off. I sure hope you guys are right about it peeling off but even if it bonds I figure I can sand and scrub it off with alcohol or maybe vinegar.

I read somewhere that Payson sometimes used plain old wax paper. The writer (Dave Carnell?) said he tried it but the joint was curing in the sun and the paper got baked into the epoxy and wouldn't peel. Of course, Payson was known to use polyester resin so that may be how he got away with it.

Oven paper doesn't contain wax! (For obvious reasons) Not to be confused with "wax paper"...

I have had good success with freezer paper. It is like butcher paper but with a plastic coating on one side. Pulls right off of cured epoxy.

Originally Posted by woodeneye

Hi Mick
I found oven paper does a great job at producing a really slick "no sand" surface too. Just lay it over the epoxy coat and give it a roll, removing air bubbles and leave it on until the epoxy goes off. Worked a treat on my foils, so am going to use in on the hull panels as well.

Some "how to" photos and some description would be great Bruce.

MIK

I pulled the parchment/oven paper off my splices early yesterday. It didn't take much effort--I believe a little wind would have lifted the paper right off if it got under an edge. It was like magic--the paper stuck perfectly to the wet resin but curing somehow made it let go.

I just cut the paper slightly oversize so there were edges not bonded to anything; I wanted something I could grab and lift. I didn't get the glass-smooth surface the Lexan gave me but it's smooth enough. What's left behind can be easily filled and faired.

Originally Posted by MiddleAgesMan

I pulled the parchment/oven paper off my splices early yesterday. It didn't take much effort--I believe a little wind would have lifted the paper right off if it got under an edge. It was like magic--the paper stuck perfectly to the wet resin but curing somehow made it let go.

I just cut the paper slightly oversize so there were edges not bonded to anything; I wanted something I could grab and lift. I didn't get the glass-smooth surface the Lexan gave me but it's smooth enough. What's left behind can be easily filled and faired.

Excellent! I bet this has saved you a lot of sanding, and the best part is it's cheap as chips!

This is a nice tangent we got onto...maybe a new thread?

marking out for seat cleats



pattern made for tank top out of ply scribed to sides of hull and hot glued together. The pattern is not made directly atop the cleats, but on 6mm spacers...to account for the bevel



you just measure the gap to determine the bevel needed to fit the actual tank top.



The patterns can be reused again and again, but thrown away or recycled, too. I have to fit the bottom after my family gets over our like FIFTH round of cold/flu this season.

I'm also a little behind because I found that my midship BHD was not symmetrical, yet all the measurements were spot on. If you trace a rectangle, and flip it over across its centerline and retrace you should get the same lines...that was not the case in my bulkhead and I spotted it in the hull. It is uncanny that the measurements were correct, the diagonals of the bulkhead were within a mm but the tracing technique revealed the asymmetry...it was like 3/16"...I like to work with in 1/8" tolerances generally!!! So test your bulkheads this way.

She is under a tarp in the driveway, been that way for a couple weeks now. Can't wait to get back to her. So, this has been my main project. The other ones are driving me to it!