1708 overlap bottom up or top down

This is the place to post your ideas, thoughts, questions and comments as relates to general boatbuilding and reconstruction techniques and procedures (i.e. recoring, epoxy, fiberglass, wood, etc.)
Post Reply
sailingbud
Bottom Paint Application Technician
Posts: 11
Joined: Mon Jun 07, 2010 3:13 pm
Boat Name: Wasasha
Boat Type: Nantucket Clipper, Flying Scot

1708 overlap bottom up or top down

Post by sailingbud »

The weather and other distractions are letting me work on my boat again. The hull has had the gelcoat and a layer of fiberglass removed. Now I have 1708 ready to cover everything below the waterline. The epoxy is ready to mix. The hull will take 3 rows of the biaxial cloth.
Is it best to go from the keel up or waterline down? The keel is encased, no keel bolts or seams.

Walter
LazyGuy
Candidate for Boat-Obsession Medal
Posts: 349
Joined: Mon Jun 11, 2007 9:31 pm
Boat Name: Paper Moon
Boat Type: Luders 33 (Allied Boat Co.)
Location: Mystic CT

Re: 1708 overlap bottom up or top down

Post by LazyGuy »

I think Glen has the right idea, rather than letting gravity fight you as you work from the keel up, tape the dry cloth at/above the waterline, wet it out and as you squeegee out the excess, work it down toward the keel. Along the same lines as a roller tray, look in the wall paper area of Home Despot for the trays used for wetting out rolls of wall paper. Use it to catch the squeegeed epoxy. Once the sheet is all wetted out, if it is properly saturated (not too wet, not too dry) it will have no trouble sticking to the hull. Use a sharp sheet-rock knife to cut the glass at the waterline.

Yes, pictures are great.
Cheers

Dennis
Luders 33 "Paper Moon" Hull No 16

Life is too short to own an ugly boat.
Carl-A259
Master Varnisher
Posts: 104
Joined: Fri Jan 15, 2010 3:07 am
Boat Name: Romper
Boat Type: Pearson Triton hull705
Location: Georgia

Re: 1708 overlap bottom up or top down

Post by Carl-A259 »

As you are layering the cloth, wouldn't you also want change the direction of the weave of the cloth, especially with biaxial?
Zach
Boat Obsession Medal Finalist
Posts: 684
Joined: Wed Jan 25, 2006 6:28 pm
Location: Beaufort, North Carolina
Contact:

Re: 1708 overlap bottom up or top down

Post by Zach »

It depends on the boat, I'm assuming you've got a round wine glass hull and not a flat bottomed something that is already flipped upside down... If it is a fiberglass hull that is still structurally sound, why the 17 ounce? I am kicking myself about grinding off the gelcoat on Pylasteki, and not just putting a layer or two of finish cloth over it to keep the cracks from showing through the paint.

I detest taping cloth to anything and trying to wet out through it, as it is like watching paint dry, and there always seem to be major dry spots. Do a test run and grind off the panel you tried and see how much dry mat there is under that 1708, even after air rolling it. Try a piece of 1708 wet out from only one side, if it is anything butt flat surfaces, and you haven't puddled the resin up, the mat seldom gets wet. You can do that with polyester wetout resin, but epoxy is so much thicker it doesn't work very well. Stuff that isn't as heavy as 17 ounce is fine, particularly finish cloths... and up to a straight 17 ounce biax with no mat is a different story, you can wet it out in place successfully, and it is easier to deal with that way without it fraying and unraveling, but it isn't as easy to work with in general as it falls apart in your hands. If you must, tape all the edges before it comes off the roll. Tape it on both sides of the edges and cut through the tape, then tape the cut line. if you can keep the edges from moving apart you stand a chance... Then you've got to get it in position, take off the tape, tape it down, and then either grind off the tape or cut loose the taped area while the cloth is green.

The benefit of all that, is that 17 ounce with no mat takes a lot less time to get straight and fair after all that work of taping. It just isn't "easy" to do the actual fiberglassing... it takes less resin, is stronger if used with epoxy, and probably saves time at the end of the job, but golly... the tape!

Three layers is a lot of weight, why do you want three, and what kind of boat is this? If you work out how many square feet you have to glass, 1708 weighs 23.75-24.2 ounces per yard. A yard of fiberglass that measures 50 inches wide, is 27 inches long as an FYI. The glass is half of the equation, as you are going to use an equal amount of resin to wet it out. 24 ounces of cloth, 24 ounces of resin 50/50 for a hand layup. 48 ounces to the yard... Then to fill the weave of the cloth you are looking at putty weight which isn't light... (Adtech proseal is my vote.)

That's a whole lot of cost, and a whole lot of weight.

All that being said, here is how you do it:

If you have help, the easiest way to do this job is upside down. Not you, the boat.

Start with a 4x8 sheet of plywood with plastic stapled to it, and lengths of cloth cut for each spot going from the waterline to the keel. Cut off the first 3-4 inches of any piece that comes off the roll and doesn't lay flat. You can't grab just the en with your thumbs and not pull a big pucker in the cloth. Be careful with it... otherwise you won't get the first 4-5 inches to lay down to the hull! Loosely roll/fold the cloth with no creases... these pieces numbered in order, with an arrow pointing to the bow and an arrow pointing to up. I put a Starboard or port, and A and B, then the numbers. After 8 hours, all the stacks look the same, and if you get the wrong piece and it is to short/out of order you end up getting your scissors covered in epoxy, and that is a sin. Make the stacks, inside a big industrial trash bag incase you get a rain shower that comes by and tries to destroy your fiberglass... (True story) Make sure everyone is read in that grabbing the wrong piece is bad juju. This means your piles need to be organized, well lit, and everyone with their thinking hats on. Speaking of hats, wear one, I lost a pony tail doing this...

You want a pair of Wiss industrial shears for cutting that much glass. Try not to get them covered in wet epoxy, as they are only perfect and new once... Bodi co sells them reasonably. http://www.bodico.com/

I would strongly consider glassing the keel with two different widths of cloth along the length of the boat, rather than trying to wrap it under the bottom and go up the other side. Say a 2 foot piece and a 1 1/2 foot piece. The cloth coming down each side on the first layer butts the 2 foot wide piece, and the next overlaps and butts the 1 1/2 piece. Leave the first layer where it butts, but with a bit of slack where it is truly a butt joint having up to a 1/2 inch gap between the two, and cabosil pulled between them and not an overlapping seam. You cannot fair the bottom of the hull smooth with no bumps without a whole lot of putty, if you try to overlap the first layer. You'd have to grind down the outer layer totally, and part of the overlapped cloth... which is not as strong as having one good solid overlap that is there to stay. You'll also want to come up with how you are going to taper your three layers to nothing. Think it through and stagger out the joints under the water so you don't have a "bump" and that you don't have to grind a taper in it so it looks right. The other way is to stop shy of the waterline and pull putty from 3 layers thick (Which is just shy of 3/16ths thick with a human doing it and not a vacuum bag...) to nothing over 6 inches or so. Trying very hard, to keep the edge of all that glass under the waterline at all times, only seen when heeled over.

The way I do bottoms, topsides is with two layers, the first piece is a half width of cloth starting at the bow. Now a full width piece butts that one. The next piece goes back to the beginning and lays over both pieces, but only half way into the full width piece that is the first layer. The next piece goes on the first layer, and the next overlays it and so on until the boat has two layers of cloth on it.

You may experiment, I roll the hull with neat epoxy... (nothing in it) have the guy wetting out cloth pass the roller up before applying the wet out cloth. It makes it easier to re-position and makes sure you don't have dry spots between the glass and the hull, which is very important. You can mix up a slurry of cabosil, and spread it around any details, chines, reverse curves or the whole panel if you are having stiction issues where the glass wants to fall off the hull. At times it is handy, but it is an extra step. Try it without first, with it you want a glaze coat of pretty thick stuff, which is easier to say than to do as it pulls like peanut butter in january... but no notched trowel, grab a hand full in your glove and smear it on the hull, with the other take a plastic squeedgee and take almost all of it off. Leave only enough goo that you can see something on the hull, and it is wet, but no clumps as it doesn't go through glass no matter how much you air roll it which means that thick patch of goo will later be a high spot.

This is a three guys easy job, a 2 guys that know what they are doing OK job... and a 1 guy, 7th layer of hell job. (1 guy needs to ladders, and some rope to hang the PVC pipe off of... or to wet it out in place. It is much easier to do with the boat upside down, but isn't that bad with it upright so long as you can get the pace down of what it takes to get the cloth stuck to the hull and not fall off into the dirt. It also helps to have the boat as high up as possible, without needing staging... as someone has to crawl under it and get the turn of the bilge. You will have some lossage go gravity while you get the hang of the motion. Don't let it keep you down, that is how modern art is made...

Wet out the cloth with a paint roller on your table. Use a plastic paint roller tray (not metal, as the metal in sunlight makes epoxy go atomic...) use cheapo green fuzzy 1/2 inch nap paint rollers on a roller frame, as they last long enough. Don't pay more than a buck for two of them... Use Slow, or extra slow hardener depending on temperature. Pour some in the roller tray, and pour some on the table. Flop the cloth into the resin puddle, and roll it with the paint roller, flop the next piece of bit of cloth into the resin puddle, throw some resin along the length and so on. Weigh a couple of shots of cloth, and mix the same amount of resin so you know what it looks like, and how much resin it takes... 50/50. It goes quickly after you know about what it looks like is "enough" before it starts soaking in. It will look really dry for a while, and you will need extra to roll the hull... also don't forget that the roller is going to soak up quite a few ounces. The first piece takes a lot to get started but once everything is wet the next few take less resin.

You really need a row of pots that are sitting on something level so you can pour out of a 5 gallon bucket 3-4 pots at a go, and a row with hardener. When you are through with the mixing bucket, go line them up in order. This sounds like a waste of time, but it is good quality control. If you have a pot that did not kick off, you have a shot of glass that did not kick off. Make sure that no matter the "rush" that everyone is stirring thoroughly, and that if it is dusk... that the pots that are sitting ready to mix, are far enough away from the mixing table that you cannot grab a pot of resin and wet out a shot of cloth and not have hardener.

You will look like you plucked a dozen chickens while covered in honey, if you have to grind a 4ft by whatever length of cloth off the hull of the boat, and then acetone wipe all the semi-hardened epoxy off. This isn't happy stuff, but the process above keeps you in the know. The day after you do your glass work take a pocket knife and scratch along the length of the work and feel for any soft stuff. You should get shavings off of everything and a hard scratching sound. If its not right, fix it.

Back to wetting out...

I like to make a pancake of the cloth on the table sort of folding/rolling it up as it goes, and then roll/smash it together in to a 6-8 inch wide couple inch thick patty of fiberglass with a wet paint roller (think... dripping) then roll this pancake of cloth on to the a piece of PVC 1 or 1 1/2 inch pipe that is 6 or so feet long.

Have two guys grab the pipe unroll about a 6 inches to a foot off the end and stick it to the boat. Then start unrolling the cloth rubbing from the center of the roll outward keeping the pipe fairing close to the boat as you do it. With the first 3 feet stuck, you are pretty much home free. The first foot is easy, the second foot is faster work.... at some point take the pipe out of the equation, and switch from gloved hands to air rollers and squeedgees. It helps to have multiple sets of squeedgees, roller frames, and plastic spreaders and a bucket of acetone to toss them all in and cycle them through the day. If you don't stop to free up your air rollers, you have to burn them off... and that isn't fun. Pass the pipe to the wetout guy, or have a designated pipe hanging spot, so that it doesn't end up in the sand. Sand and fiberglass are bad news when combined as its hard to grind sand.... rock clumps under fiberglass are hard to wet out, and turn into high spots. Spot your dry places in the glass, and roll on more resin.

The motion is kind of like kneeding dough with your fingers. You are smashing the cloth to the hull with the palm of your hands, but at the top and edges you are wriggling your fingers, together and apart while pushing out towards the edge of the cloth. This loosens the weave of the cloth and take out any heckles that pop up. Don't cut any darts, or try to slice any bad wrinkles, they will come out. Sometimes you have to pull the roll back off the hull, and start back over... no big deal if things go far out of wack. You are just taking something that is flat and wrapping it around a basketball... it will do it, you just have to loosen the weave enough to let it.

The way this goes quickly, is to get two pieces up and air roll the first one and half of the one you just put up. Only air roll one half, as you can fix the dry spots in the first piece and that half, at the end of each piece going up. If you air roll it all, every time the dry spots don't wet out as easily as if you leave the whole mess wet. Then your wet out guy and one helper goes down to the wet out table and rolls the cloth on the pipe, carries the stuff up. When you have a few pieces up and they are starting to look green, and like they won't fall off the hull if you roll some proseal over them, mix up some up and have the wet out guy roll up to where you are working.

If you must stop, or have a stopping point before reaching the end, or if you are working by yourself in small runs you want to get your hands on some peel ply. When you know your spot to stop, mark out an area on the hull and get the cloth up to there. Do not proseal, or otherwise spread microballoon on the last half of a piece of wet cloth you are working on. Take acetone and wipe the hull down of any gooeey hand prints on the dry part beside your mark. Put on your peel ply. In the morning or the next time you start, peel off your peel ply, and sand the fiberglass with 40 grit to give it some tooth. (belt and suspenders, peel ply is supposed to be enough, but I want scratches...) then start back up your wetting out process.

Getting the bottom fair afterwards is another fun one.

The easy way is to sand up and down with 40 grit and take off all the inconsistencies you can see. Then take a batten and double check that there are no hills or valleys. Then take an aluminum piece of bar stock and mix up a whole lot of putty and get all your friends to hold it evenly spaced, and spread putty on the bottom of the boat and screed the putty with this big long batten. Go back and fill any holiday's and holes and screed it again. Ideally you can do almost all the boat at one go. For speed you really only need the leading edge and front 25% of the length as the flow has separated past there.

If you are a masochist, sand vertically only with rotating tools. From the bottom of the keel to the boot stripe. Long board with flexible boards only along the length of the boat. Take off pass after pass, and keep your sandpaper fresh... If you only groove the hull with vertical passes, you can span the lows the spinning tools made with your long board, and fill them with shorter battens. You can get her as smooth as a babies butt fairly quickly. Big long boards do a better job, but 3 feet is about all she wrote for one man on a flexible board. You want Mirca Abrasive mesh in 40 grit and 80 grit on a 4 1/2 inch board, made out of 1/4 or 3/8ths marine grade plywood, with 3M's hookit velcro glued to the face. Grips and handles depend on your choice. Some people like dowel rods, some like wooden square blocks, others hoops of wood like a hand rail. All of the above work too, so when you get a cramp you can change boards.

Entertainment:

Bonus points, if you learn early to push the wrinkles of the cloth to the other guy, fast enough he/she doesn't notice what is going on, not only do you look real good... they get very, very good at the process, very quickly. Or they swear off fiberglass... ( I kid, I kid... though one of the guys I started out working with did fess up to doing this... to me... when I still had a pony tail.)

Good luck,

Zach
1961 Pearson Triton
http://pylasteki.blogspot.com/
1942 Coast Guard Cutter - Rebuild
http://83footernoel.blogspot.com/
sailingbud
Bottom Paint Application Technician
Posts: 11
Joined: Mon Jun 07, 2010 3:13 pm
Boat Name: Wasasha
Boat Type: Nantucket Clipper, Flying Scot

Re: 1708 overlap bottom up or top down

Post by sailingbud »

Greetings all and salute to all veterns. Us old vets need to keep supporting the newbies. OoooRaa, Semper Fi.

Thanks to everybody who gave their opinion here.

I have laid up 17 oz biax, no mat, and accomplished this with one helper. My boat is a 32ft sailboat and turning turtle was not an option. I did start at the line where the grinding had been done, all gelcoat and the first layer of mat had been removed from just above the waterline down. My boat has a 4.5 ft draft and waterline 23' so my pieces of biax were 25', 20' and 12' long and I cut each at 27.5" width.
Before application the entire hull had all voids ground out and patched with either cut outs of biax and epoxy or cabosil for shallow indentions. The sides of the keel outboard of the aft bilge were in very bad shape requiring 2 more layers of mat to be ground out then that area built back with the biax. After that the entire area was very solid and well saturated with epoxy no more dry mat delamination or blisters. The entire surface was blown off, wiped with acetone then that wash was repeated and dried.
With one helper, my girlfriend, we rolled epoxy neat over the surface being covered by the cloth rolls being applied horizontaly from the top down. The resin was allowed to get tacky enough to hold the biax then we rolled the lengths off a PVC pipe into place then wetted through with more resin till clear.
We did the next layer down the same way with some overlap. It was important to work from the windward side back as it helped hold the fabric against the hull instead of turning it into a wet very sticky sail.
My help had to go to her real job so I finished the keel alone. It was only 12 ft so how bad could that be?
It was pretty bad. When I found myself laying under a blanket of wetted out biax I realized how much she really meant to me. Did I mention that she is the most wonderful woman in the world?
Anyway, when working alone it is critical to make sure the resin on the shady side of the boat is really tacky enough before you try to apply the cloth. Be very patient.
I finally pulled the very messed up piece of cloth off me and the hull and spread it out on non-stick backing paper. That gave me some help to support the biax and hold the resin in place. I still removed the backing paper before it kicked and rolled out the resin and pushed out bubbles with a scrapper.
I still have a lot of work to fair and sand then paint but it has been a big step and my hull is sound if not just a little rough at the moment. Next step is getting a little closer to my orbital sander.

Thanks for the comments,

Walter
Carl-A259
Master Varnisher
Posts: 104
Joined: Fri Jan 15, 2010 3:07 am
Boat Name: Romper
Boat Type: Pearson Triton hull705
Location: Georgia

Re: 1708 overlap bottom up or top down

Post by Carl-A259 »

Walter, I'm impressed with your work to refit this hull, as a hobby boat refurbisher I can't imagine the scope of such an undertaking.
Zach , my Triton has no impact damage to the hull or deck and except for the cockpit sole no soft coring. It is however just a maze of spider cracks in the gelcoat. I haven't remove the bottom paint yet so I don't know what's under it. I have no desire to remove the gelcoat, I just want to fill and fair, the cracks are very small but they are every where. My thought is to just sand with 60 or 80 grit clean the deck and hull with acetone, soap and water and coat with a 2:1 epoxy filling the cracks. Maybe adding some silica to thicken on the vertical surfaces. Do you think this would add any life to the surfaces? Thanks Carl
Post Reply