Hull lamination

[jerome]

Told you guys İ was good at asking questions.....You want it ? There it goes !

İ was wondering if anyone has used, or thought about using, peel ply for laminating cockpit or hull. İ should do my cockpit in the next days and was initially thinkink about laminating without peel ply, wait for the "green stage", lay a thin coat of fairing filler thickened epoxi (without any need to sand before) just to fill the weave, let cure and sand for priming.
But then İ used peel ply for the first time in my life on my rudder and Looooved the stuff ! So İ browsed through the web and actually saw a lot of hulls being laminated with peel ply. İ guess the only disadvantage is that İ will have to sand it all (lightly) and remove amine blush before İ apply the final coat of fairing filler thickened epoxi.

Which solution will give the best result ?

[Chad]

Actually, the biggest plus of peel ply is you don't have to sand it, and there is no amine blush. The peel ply's woven texture leaves a great toothed surface for additional bonding or coating, and the blush occurs on the outside exposed surface of the peel ply, which is removed after curing. Also, a peel ply surface takes much less additional filler to fill the weave and make smooth.

The biggest hassle with peel ply is that it doesn't "drape" as easily as most woven reinforcements (glass or carbon), so it's harder to get it to conform to the tight bends or compound curves of detailed shapes. But decks and hull panels are no problem. I buy nylon "sport fabric" from the fabric/sewing store for quite a bit less than "real" peel ply from the composites shops- works just as well (but try a sample before committing large parts!).

[jerome]

Well that is definitely something İ did not know ! So no amine blush and great surface for additional coating ? İ need no more..........except buying a big roll of peel ply ! Thanks for the advice.

[Kevin]

I'm going to try it on my rudder. Looking forward to reporting back.

Many moons ago on the .org site there was a discussion of using strips of plastic in a similar way. It would leave a smooth finish, but the blush would also not develop like it does in open air curing. I was basically done taping at the time so it was too late on the advise column to help me much. But the idea was you had a strip of plastic (like 2mil stuff) and a strip of cloth or tape. You wet out the glass on a table and then took the whole strip with plastic to your boat and laid it into position. Use a scraper to smooth it out to the joint and allow to cure. Then come back and pull of the plastic. Assuming no voids you have a completed section with no need for a second coat to fill the weave.

Cheers, Kevin.

[Chad]

Only problem with plastic is that it doesn't let the excess resin through, so you end up with a resin rich (heavy) laminate, UNLESS you are able to aggressively squeegie the part and push all the excess resin out. That's unlikely with big panels, and more unlikely with shaped or contorted tapes. And the slick surface needs sanding for any additional bonding or coating.

[jerome]

That is right Chad. İ have used that plastic strip technique and it sure gives a nice finishing but there is indeed a tendency of leaving too much resin in.The peel ply is another world. And by the way İ did not use any absorber cloth but the end result was much dryer, tighter, nicer looking than with the plastic strips. Kevin, you will love the stuff !

[jerome]

by the way guys, here goes another one of my questions. That is straight out of Lamination 101.

-what methods / tools do you use to best apply the float coat (fairing filler + resin) ?:
a-squeegee
b-brush
c-foam roll
d-all of the above

[jray]

I don't know what the "Correct" answer is but I used a foam roller and a squeegee. My answer is whatever works!!

[Chad]

For small parts I'll use a cheap bristle brush, for something bigger a roller. Brushes always leave brush strokes and drips with epoxy, but rollers rarely do. For small parts, it's hard to justify (in my mind) all the lost resin in a roller and the cost of the roller and disposable pan, versus a few extra minutes of sanding.

Squeegies only seem to work for initial coats on dry wood, and over cloth they leave too little resin behind to actually fill the weave. If you add enough filler to the resin that the weave does gets filled, it's very hard to control the smoothness- you end up with lots of ridges and valleys. This can be ok if you know you have significant fairing still to do, but it's a lot of sanding if all you wanted to do was fill the weave.

[Mist]

Hey Folks,

I have another thought to share a peel-ply especially if you buy West system products.

West system sells peel-ply both folded and on a roll. The roll is much larger but lays nicer in the wet epoxy. The folded stuff will leave a ridge every 16" inches or so where the fold in the ply was. I suggest the folded choice if one is vacuum bagging otherwise pick something on a roll.

[Kevin]

For spreading the sticky stuff, I used spreaders (4" plastic ones) most of the time. I would definitely try a foam roller on a large 2nd coat situation. I found that brushes left a lot of epoxy on which I usually wasn't looking for. And I plan to use chip brushes on my rudder layup to apply and then a spreader to even it out.

I would agree on the folded versus a roll. Creases will always show through so if that matters with your part then it's a bad idea.

On a separate note, I tried the shrink tubing from Soller composites. I basically cooked the epoxy while I shrank the tubing. On my next ruder I'm planning a spiral wrap of peel-ply.

[jerome]

Hi guys,
İ laminated my hull yesterday. The great thing is that my wife helped me out so we each took care of one side with me running from one side to the other to make sure everything was ok. We ended up doing a pretty tight lamination. Not too much excess resin. Good job !
Then, after the whole boat was laminated we applied the peel ply....For sure, some sections were almost dry and the peel ply did not adhere properly. Not so good.... But İ guess it is no big deal and will let the hull dry for another day and rip the peel ply tomorrow.

Because my fiber roll was short (80cms) , İ ended up overlapping 4 sections giving me a seam at about mid panel on both sides and one in the center line. My idea is too sand and fair that seam, as well as fair any other additional spots, and then apply the float coat. İs that correct or should İ apply the float coat first, then fair the seam and other spots ? My hull looks pretty decent because İ took my time to do all fairing before laminating so İ am really mostly left with the seam to deal with.

Also, because İ did not use the peel ply properly, İ guess some of that amine blush will be left on the fiber (even though İ used 207 hardener wich is suppose to leave no amine.) So should İ water sand that before the float coat ?

İn that case İ guess the steps would be:
1- water sanding to remove blush
2-fair and sand
3-apply first float coat with a little fairing . Check for fiber marks
4-eventually apply 2nd layer of float coat wet-on-wet (no sanding in between float coats)
5-final water sanding with 220 .
6-apply primer (Epoxi primekote in my case) 2 or 3 layers wet on wet
7-water sand with 220 and then 320
8-PAİNT !

Looks like a lot of work still but İ want to make sure İ got the right sequence.

Thanks

[Kevin]

Jerome,

Sounds like you had a very productive weekend !!! That boat is going to be in the water in no time.

1. For the blush you can wash it off, no sanding required. A scrub brush and a bucket of water should take care of it.
2. Yes, since you were fair to start with, your job now is to fair out any cloth seams. I'd use an approach similar to drywall taping. Start with a wide knife (8" or so) and then come back and add a 2nd coat with an even wider knife (10" or 12"). If you do then wet on wet you probably will save yourself a few headaches. Your goal is to find the low spots and leave almost nothing on the high spots. I filled and sanded a ton (lots on the floor) and anything you can do to avoid that would be good. I didn't use wide knifes which was probably to my own detriment. You also want to build up your chines how ever you want to finish them.
3. if your peelply didn't help you to have a filled weave, then you want to be careful with the sanding so yo don't go through your glass. I used a scrapper so I had to put on 3 coats to really fill the weave on my hull. I probably used some fairing compound to do that job as I became inpatient and had seams to fix too.
3a. You'll also want to do a "post cure" before you do final fairing and sanding. I had lots of time on my side so the epoxy had fully cured up. If you want it done now then Pull the boat out into direct sunlight for an afternoon and that will probably do the job. You need to get the epoxy up to 105-110 degrees F to achieve a full cure. If you don't do this now, it may happen when the sun hits the boat after you paint. That's what they call "print through" because the pockets of epoxy between the fibers cures and expands leaving a fabric print through on your finish.
4. You probably need one coat of epoxy over any fairing to fill pin holes from those micro balloons or what every cool filler you used. I'd add pigment (different color than primer) so you'll know if you sand through the primer.
7. The epoxy primers really setup hard. I let mine fully cure and then sanded the heck out of it which took a lot of time (and cussing). Supposedly if you do it within 24 hours it's not as bad, but I think you have to deal with gummed up sandpaper because the stuff isn't fully curred.
8. What a awesome day that will be.

Great finishes are all in the prep work. Don't skimp on a step because it will just make for issues down the road.

Keep up the great work. Kevin.

[jerome]

Thanks Kevin,
that concludes the working plan İ needed. The only really difficult stuff in all of your recommendations is the post cure because:
-the weather currently sucks in Turkey (rather cold and rainy)
-İ have no real easy way to drag my boat outside (no wheels on the jig). İ could always ask the guys who helped me out flipping it to just carry it outside but....
-İ have no place to leave outside of my house since my garage exits straight onto the condo driveway !

Only possible post cure would be to wait for the summer days and let it cook inside the garage.....but İ really dont feel like waiting all that long to splash ! Everybody else has done that post cure ? İ know it is probably an important recommendation but İ cant remember reading that from the blogs.

[jerome]

Oh yeah, another doubt.

You mentionned building up the chines to whatever way İ want. Thought about it but İ am a bit confused because that would mean having a substantial amount of fairing filler, or in the best case cenario colloidal silica, on top of the fiber and right underneath the paint. Would that edge be solid at all ? İ mean if the chines are built before and then covered up with fiber cloth than they probably have some strength, but building them after laminating sounds strange. Wont they most likely break away after putting the boat a few times on and off the trailer ?

[jray]

Everybody else has done that post cure ? İ know it is probably an important recommendation but İ cant remember reading that from the blogs.

I had the same questions some time ago and got diffrent answers, so I called the tech line for the epoxy product I'm using and got their take on what the product needs to cure fully before painting. Just a thought if you can call or drop a e-mail to the manufacture of the product you are useing they won't steer you wrong.

[jerome]

Jon,

good point. İ am using WEST system epoxi. did you use the same ? İf so what did they tell you ?

Nortorious, always quicker to build that oven than to wait for the hot weather but it will take time and money no matter what. İ was not really counting on that in my splash schedule

[jray]

I have been using System 3 products for the build. The information I got from them was not to worry about post cure. I have no info on what West System recommends for their products. Drop them a email. My best advice.

Edit, I am using their finish coating products which might have some bearing on the recommendations they gave me!

[Kevin]

Jerome,
Sorry, didn't mean to totally mess up your splash schedule. I didn't realize you had crappy weather in April too, it's barely 40 today and it snowed yesterday. Did a quick search and found a few tid-bits. But it's probably best to contact the technical guys at WEST SYSTEMS. They would be happy to help you figure out exactly what you need. That's good advise from Jon. And those guys built an i550 too. It was a concern for me because I was painting my boat a very dark color which means the surface temps go through the roof in direct sunlight.

[jerome]

Hi guys,

as suggested by Jon İ got in contact with WEST. Here is the full transcription. And Kevin, you are once again right about your concern with dark colors...İn my case İ will go with White, Red and Grey and İ might skip the post cure at 60C !

MY EMAİL:
"I have used WEST epoxi for the construction of a small i550 5,5 m sailboat I am buiding in Turkey. I believe you guys have done the same with your Hot Canary.
I just laminated the boat and my fellow builders are telling me I should do a post cure before painting otherwise the weave of the fiber will later see through the painting Weather in Turkey is currently rainy and cold. I can maintain an average of 22 Celcius (71 F) in my garage (where I am building) but not above that. Cant drag the boat outside either for a \\\"sunbath\\\". I could however buy small electrical heaters/blowers and try to wrap a plastic film of somekind around the boat to simulate an oven effect and try to raise the temperature but that will take some time and money and I am not sure to what degree I can elevate the temperature. Again fellow builders have recommended minimum of 110 Farenheit.
Do you guys actually think it is necessary ? I used 207 to avoid amine on hull lamination, 206 for the rest of the boat.
I am not so worry about strength as this external lamination is more to make the hull watertight that to really increase strength. I am worried about the paint job.
If necessary, to what degree and for how long should I try to elevate the temperature ?
Thanks
Jerome"

WEST ANSWER:
"Jerome:
We did not post cure Hot Canary before painting. We usually only concern ourselves with post curing WEST SYSTEM® Epoxy if the hull is fiberglassed and if it will be painted with a dark glossy color. Hot Canary was a soft yellow and should not get too warm when exposed to sunlight. Typically light colored boats do not telegraph the fiberglass pattern over time- at least not to where it is very noticeable. Dark glossy paints on the other hand mirror imperfections at an almost alarming rate so if fiberglass is involved, it is best to heat the surfaces to a temperature close to what it will eventually be exposed to so the “print through” occurs before the final sanding step. That way the visual disturbance is removed before the final paint. You could apply dark primer paint to the outside of your epoxy/fiberglass hull and direct radiant heat lamps at the surface for 4-6 hours at a time while holding the surface temperature at 140F (60°C) or so. That way print through will occur and can be sanded away before the final paint is applied.
If you choose a light colored paint, post cure is not required.
I’ve copied this e-mail to Wessex Resins & Adhesives, the WEST SYSTEM® Epoxy licensee/formulator in the UK, so they are aware of your query and so can offer comment if they wish.
Best regards,
Tom Pawlak"Technical Service

[jerome]

Me again, İ need a quick advice.

doing a close examination of my recently laminated hull İ found three spots with bubles. All of them are on the hull bottom to sides edges and are about 1inch long by 1/4 inch wide. Not the biggest bubles, but bubbles not matter what.
Therefore do you guys recommend to:
-leave them as is
-sand them off and simply fill and fair with fairing putty
-sand them off, re laminate over a slightly larger area, fair.

Thanks

[Ron Bowman]

Hi Jerome,

You might be able to inject a little epoxy into the bubble with a syringe and clamp or otherwise hold the cloth against the hull until the epoxy cures. If that doesn't work, I'd be inclined to sand them off (just the bubbles), fill and fair.

Ron

[jerome]

Ron,

the cloth has hardened therefore it is almost impossible to do as you suggested. Although İ wanted to avoid doing this , İ guess İ should do the full job like sugested by nortorious.
Tell you one thing guys, İ am getting good at sanding and fairing !

[Kevin]

3 simple steps...
Pop them with your tool of choice ( I used a dremel with a little carbide bit). Might be best to make 2 holes to allow air out of the second hole.
Fill them completely with neat epoxy using a syringe.
Fair over them and move on.

You usually attain expert status at each boat building skill when you are about 95% done with that particular task. If you are getting good at it, that means you are almost done .
Kevin.

[jerome]

Arrrg hhhh ! That good piece of advice came in a bit too late. Sanded the shit out of them last night. But their are minor bubles, really, and they dont scare me. İ will laminate them over and fill confident the chine will look good and strong aterwards.