Applying Fiberglass

[cliffg]

Well here goes again.

I plan to cover the recored deck this coming weekend. I got some biaxial cloth from Jamestown Distributors. I have reglassed some small areas already and have read and reread the West System booklet. However, I have some trepidation. Let see if I have this process correct.



West System recommends:

fairing everything before apllying the cloth


using the dry method. Where you place the cloth on and then wet it out in place.

apply all layers of cloth the same day

let each layer get tacky before applying the next one

Does the above sound right?

Next question. While reading the booklet one section describes repairing a large hole and suggests applying thickend epoxy before the first layer of cloth. I am guessing this is because the surface would be vertical rather than horizontal like the deck would be.

Since this is, for me anyway, a fairly large area I don't want to screw it up. Which I am quite capable of doing!!!!

[grampianman]

I must say I followed pretty much the same path as you and yes, it was scary until I was finished. Then, I could say it wasn't so bad. On my 23 footer, I covered the deck and cabin-top with biaxial cloth. I dry fit all of my pieces and marked the deck with a pencil so I knew exactly where the pieces lined up. I overlapped pieces by about two inches. In my case, I brushed on regular epoxy to help hold the pieces in place, THEN I proceeded to wet out the cloth. My mistake here was to just brush on epoxy (unthickened) and dab it into the cloth with a paintbrush rather than use a roller. The roller would have squeezed a lot more air out of the cloth and I probably would not have used quite as much epoxy. I ended up having to sand and fair more than if I had used the roller, as well. 20/20 hindsight. I also worked as much as I could comfortably handle within my work timetable. I started at the bow and worked back toward the cabin, then split down the sidedecks. This took me one weekend. I then went up and did the cabin-top. That was a day. So, basically over a two weekend period, I completed the layup of the deck. The sanding and fairing - well, that's a whole other looong story. I only used one layer of biax as I had re-laid the original deck layer back on, so the biax was for extra strength and waterproofing.

So, for what it's worth, that's my story and I'm sticking to it.

Cheers,
Ian
Wing & a Prayer.

[Figment]

Forgive my spotty memory of your project... are you covering the entire deck with biax, or just taping seams?

My only comment would be that I don't have the patience for the "let each layer get tacky before...." part. As soon as one layer is thoroughly wet (which takes some doing with heavy biax) I'm on to the next.

I think the "thickened epoxy" part has more to do with the potential to float a resin bubble between the substrate and the cloth, and such thickness of raw resin would become quite brittle. If your deck is fair*, you shouldn't have such issues, but it certainly couldn't hurt.

*I know that in this stage of my recore, the deck was nowhere near fair. I saved the fairing for later, just prior to the final layer of light cloth.

I understand your trepidation, but it's really not all that difficult. It's not exactly a "pleasant" process, but still not that difficult. Put on some good music, get yourself in a groove, and just keep working along.
It would be helpful to have an assistant on hand to mix the next pot of resin while you're applying the current pot. This allows the use of smaller batches. In addition to preventing accidental cook-off, smaller pots are just easier to handle and lead to a much tidier experience. Anyway, helpful but certainly not critical.

[Tim]

...fairing everything before apllying the cloth...

The West guidelines are generally very sound, but remember that most of their MO relates to the sheathing of cold-molded wooden boats. In this case, where the fiberglass material (usually lightweight cloth) represents the final surface, the area should indeed be very fair. But this is not really the situation you're in.

For your purposes, by "fair" they really mean that your surface should be basically smooth and free from significant roughness, hard spots, or other such changes in topography.

The surface needs to be "fair" enough to allow the cloth to lay over nicely without creating air pockets, but since you will have to fair the decks after the fiberglass is applied, you don't have to get it perfect first.

...using the dry method. Where you place the cloth on and then wet it out in place.

For large areas, this is the most convenient method. For the hard-to-saturate biax, lay some resin down on the surface first, then apply the dry biax.. This will help the resin soak into the back of the material. Otherwise, it takes some doing to thoroughly wet this material.

...apply all layers of cloth the same day...let each layer get tacky before applying the next one

You can apply 2-3 layers of biax at once, if need be. If you install too many layers at once, though, you'll find that the process of rolling the air out can create depressions and divots in the surface, as the amount of resin may become too high, thoroughly softening the material. 2 layers would be fine, though.

It's smart to lay out your material dry, and cut it to shape as needed; then, mark it clearly. Do this for however many layers you anticipate using. Be sure to butt your seams in each layer, not overlap. Then, on the next layer, simply stagger the joints so that the seams below are covered with material. Overalapping seams leads to inconvenient ridges and high spots that must be faired and ground significantely.

During installation, install the first two pieces of the first layer, then go back and install the first piece of the second layer (which will be slightly shorter than the first piece of the first layer thanks to the staggered joints). Continue in this general manner down the length of your deck as needed; the first layer will always be a half width (or so) ahead of the second layer. This ensures that the material doesn't cure too much to apply the second layer in the same operation, and also ensures optimum bonding between the layers.

"Tacky" in this instance is a pretty loose term. You may find that it is better to go a bit further with the first layer before beginning the second, but the material should still be wet to the touch when you begin the second layer.

While reading the booklet one section describes repairing a large hole and suggests applying thickend epoxy before the first layer of cloth. I am guessing this is because the surface would be vertical rather than horizontal like the deck would be.

There's no need for this in your situation.

Fiberglassing really isn't that difficult. It is not a clean job, period. I like fiberglassing, despite its overall unpleasantness, and as you proceed you'll see how basic the general process truly is.

Just remember: thoroughly wet out, and get the air out. This is really all you need to know.

[FloatingMoneyPit]

I called the West support line the other day to confirm my intended process, and the gentleman I spoke with indicated that a final layer of cloth over the fairing--as indicated in the West booklet--was not necessary in the case of a new horizontal deck laminate. He did say that at least one final coat of thin resin should be applied to the entire, faired repair, though, before proceeding with the painting process. He also confirmed that gelcoat paste can be used over an epoxy repair, but to be certain the epoxy is well past curing.
Just passing it along.

[cliffg]

Thank you all for your wealth of knowledge and advice. Honestly, I feel a lot more confident now than after reading the West System booklet several times. I guess hearing it from people who have actually done the same type of work helps. Plus your explanations are so clear and easy to follow. I work in the IT industry and part of my job is writing documentation, man it's amazing how convoluted some people can make the simplest process.

[FloatingMoneyPit]

Cliffg, I'm pretty much at the same point you are. I've read the West booklet, parts of Alain Vaitses Fiberglass Boatbuilding and Repair, and Don Casey's Hull and Deck book about 100 times over the last couple years, getting mentally prepared. After getting the process in my head and walking through it mentally a dozen times, it turns out what everyone says is right: just do it.

I tell myself the following while I'm mixing batches of epoxy:
I'm not building a Cup boat
"Fiberglass work is messy, period" (Tim)
I'm using good materials (epoxy vs poly, biax vs CSM, etc.), so even a sloppy job will be far better than the wet, bouncy deck I have now
It's just labor, not rocket science
Keep working, just concentrating on one simple phase at a time, and I'll be sailing before I know it. It's easy to get overwhelmed thinking about all the work ahead.

That last one is most important, since each step takes longer than I plan for and the end seems so far away. But in reality, my own recore will probably have taken a dozen 6 hour sessions, from first cut to painting new nonskid. A lot of work, but doable and worth the peace of mind.
It all just seems like rocket science since we haven't done this sort of work before and don't know exactly what to expect at each stage.

Finished getting all my core laid in today. Another 1-2 days of laying the new topskin fabric, then fair, sand, fair, sand, fair, sand, prime, paint, launch! Could even be sailing by late next week, Mother Nature allowing.

[cliffg]

I went down today and started grinding the edges so as to hopefully lay the fiberglass tomorrow. I hadn't noticed this before but I find that the existing deck is not true, there is a difference in several places. The plywood I installed is flush with the old deck and some places it sits just below it like it
should. There's no way I can add enough thickened epoxy to level everything.

Anyone have any ideas?

[Figment]

There's no way I can add enough thickened epoxy to level everything.

why not?
What's the max difference in height? 3/16" ? (guessing that's the thickness of existing skin)

Grind down the highs, fill in the lows, that's boatwork.
You're right, the exising deck probably isn't very true at all. This means that even if the plywood HAD somehow landed evenly all around, you'd still need to do a good bit of fairing to get things to look right anyway.

It can be a tedious effort, but worthwhile. Nonskid hides many sins.

[Tim]

There will always be a large amount of fairing required in these jobs. It's the way of the world. There are so many places for slight inconsistency in thickness or height to add together and compound each other that grinding and fairing is virtually assured.

If you have substantial differences in height, you may need to install some structural fiberglass to make up much of the difference before you fair, as this will provide a more stable base than a very thick application of filler. You didn't say what the height difference was, but if it's in the order of 3/16" to 1/4", you can get away with filler alone. Any more than that and it would be prudent to add strips of material as needed to shorten the height difference before applying the filler. Fill the lowest spots with material, and then when it cures grind any high spots thus created so that they are flush or roughly compatible with the surrounding area. Then you can begin application of fillers.

These are all generalities. The more information you provide about what is going on in your case, the more accurate the suggestions you may get! I promise there is a fix for your situation, however bad it may seem now.

[cliffg]

Yes, the existing skin is about 3/16. I guess I can go ahead and fair that amount. It will seem like an awful of epoxy. But like you said it will be worth it to have the deck fair.

It seems to me that I will have to make some sort of screed, like used to level concrete. But make it consistent with the curvature of the deck to as to keep the same camber.

By the way, the Porter Cable grinder has paid for itself alreay. I do go through a lot of sand paper though. I'm going to buy some in bulk.

I'm amazed to find how inconsistent the deck to hull joint is.

As usual thanks for the advice.

[Tim]

I do go through a lot of sand paper though. I'm going to buy some in bulk.

Don't mess around anymore. It's time to buy some of the outstanding heavy-duty sanding discs from McMaster-Carr. You want the "Clog-Resistant Aluminum Oxide Discs" in the proper diameter to match your sander. (5" or 6").

Adhesive-Backed Sanding Discs: Catalog Page 2576

I am putting this information in the "Supplier Links" section so that it will be easy to find. Don't attempt a project without these on hand!

[cliffg]

I decided to glass over the outboard well and use an outboard bracket. So, last week, I removed the lazerette sole, the outboard well surround, etc. I ground everything down on the inside and the outside, hopefully tapering it properly. Today, I was going to apply the fiberglass. I put a piece of fiberboard backing, covered with wax paper, over the hole from the inside. taped it in place and put some lead pigs on it to hold it in place. I mixed up a batch of thickened epoxy, using 406 thickener, and put that on the opening. I then wetted out the first layer of glass and it would not adhere. I had cut extra pieces of glass so tried one that I had not wetted out and it adhered ok. Wetted out the next piece and it would not stick, tired applying one that had not been wetted out and it would not stick either. Mind you, this is all upside down, since the outboard well is on the under side of the hull. It is very hot and humid today so don't know if that's a factor. Using slow hardener. So I stopped, came home and decided to ask the experts.

I can glass over the inside to add strength. I must have done something wrong, any ideas?

Thanks

[Tim]

It sounds to me as if the wax paper facing downwards from your interior mold is working exactly as intended: it is preventing the fiberglass from sticking to the mold. Since you're trying to press glass into place from beneath, over your head, it can't get a good grip on the wax paper.

Or at least that's what it sounds like to me from your description!

Glassing over one's head is no fun in the best of circumstances. Whenever possible, it's best to work down hand and let gravity be your friend rather than your enemy--especially when a mold release, like wax paper, is in the equation.

[cliffg]

Tim,

I was able to get the first layer of cloth to adhere. I had applied thickened epoxy and that was ok. It was the next layer that would not stick to the first one.

Wondering if I should have wetted out the first layer while it was on.

I guess the next question is, will I get as much structural integrity if I glass it from inside and just fair the outside smooth?

[Tim]

OK...I guess I misunderstood what you were saying.

So after you applied the thickened epoxy, you tried a piece of previously wet-out glass and it wouldn't stay in place. So instead, you tried a dry piece, which did stick. I assume you then wet this dry piece out while it was stuck in place (you didn't say specifically) and it remained in place. Correct so far?

But you couldn't get a second layer to stick no matter which way you tried it? The only thing I can think of at the moment is that maybe your thickened epoxy and/or first layer was already kicking by the time you tried the second which might make adhesion difficult or impossible. Another possibility is that your material was too dry, or not saturated enough, to stick in an overhead position. This often requires more resin than you might otherwise use, and until you get the material at least partially rolled into place, adhesion is nonexistent. Often, even rolling the material will drag it right away from the surface to which you want it to stick. Experience can make or break a situation like this, as there's not always a magic thing you are doing wrong or doing right.

These are just guesses, since I wasn't there to see, obviously. Maybe I'm missing something. The good news is that if you left the first layer (whcih you successfully got to stick) in place, there's no reason to not remove blush and grind, and then attempt to laminate over the top. And the further good news is that you can certainly add your reinforcement on the inside; the net result, strengthwise, will be the same, and you may be able to get even greater overlap on the inside. You'll just have a lot more fairing to do on the outside.

[CharlieJ]

LOL- What Tim says--

" Another possibility is that your material was too dry, or not saturated enough, to stick in an overhead position. This often requires more resin than you might otherwise use, and until you get the material at least partially rolled into place, adhesion is nonexistent. Often, even rolling the material will drag it right away from the surface to which you want it to stick. Experience can make or break a situation like this, as there's not always a magic thing you are doing wrong or doing right. "

Is exactly right. Glassing overhead can be kinda like herding cats. Get one corner stuck and another peels away- sometimes onto your head *grin* Needs to be a bit wetter than usual.

I try to roll the cloth then start at one end and roll it into the wet resin un rolling as I go. Prewetting cloth and then sticking it overhead is NOT an easy thing to do. I much prefer using dry cloth rolled into wet resin overhead. Also don't try to use a piece that's too wide. If you have a wide area, just lay the glass in in strips, overlapping as you go. Then over lap the next layer in different places.

Of course IF you can coerce a helper it gets easier.

Worst job I ever had was glassing the underwings of a trimaran- 4 foot wide stuff, 28 feet long. Took three people to do it .

[cliffg]

Thanks for all the advice. Indeed trying to apply it over head does result in it falling on one's head!!!!! NOT a pretty sight.

Anyway, I left on Saturday pretty depressed. After thinking it over the only thing I didn't try was putting thickened epoxy on the exisitng layer. So went back down on Sunday afternoon, (am I glutton for punishment or what?) and mixed up a batch of thickened epoxy applied it and low and behold the next layer adhereed very nicely.

Since I can get the inside of it I am going to add 3 or 4 layers on the inside, then fair the outside and sand it. By the way, I mentioned I had covered some fiberboard with wax paper for backing. I took that off, some of the wax paper did stick to the epoxy but I had a perfectly nice and smooth plug. I had applied thickened epoxy for the first layer of cloth (biaxial). I will grind the area around the plug and rough it up as well and apply the new layers on the inside, I plan to overlap the edges a couple of inches all the way around, so I should end up with a patch that is thicker than the rest of the hull.

Now, another question. The backstay chain plate had been thorugh the aft deck and attached to a piece of glassed in plywood. I am hoping to put it on the outside of the transom, moving it back about and inch or two. Wondering how big a backing plate I should use, I plan to use a piece of 1/2" marine plywood then of course stainless steel bolts with washers. I was thinking about going to a metal shop and having a piece of stainless steel or aluminum plate made about the same size as the plywood and adding that as well, considering the strain that is put on the stays. Any thoughts on that?

Now another quesiton ( I know, I am probably driving readers away from this forum in droves) but please bear (or bare) [now that wouldn't be a pretty site] with me, but since I have successfully glassed in the outboard well (I dearly hope so) I need to add an outboard bracket. Need to add a backing plate for that as well, any advice on size, material?

Seriously, thank you all for your patience and willingness to help.

[Tim]

Both your backstay chainplate and outboard bracket will require sturdy backing plates. You may need to reinforce a wide area of the transom in order to properly support the chainplate, as a normal hull lamination not so designed might tend to allow the pressure to begin widening the holes under stress. Additional fiberglass or a good-sized, glassed-in piece of plywood or similar is the norm here.

The outboard bracket will put a lot of stress on the transom. You need a wide backing plate of hefty dimension, to oppose the dynamic forces the outboard will place on the boat--virtually all directions: weight directly down and out, side to side, angled...of course, this depends somewhat on the size of the outboard that will be used.

The long and the short of it is that both of these installations require more, not less, reinforcement, so be sure to err on the side of caution here.