Wrinkles and creases come in many flavors, not exactly sure what your problem is. Aany chance you could post some pictures? Once we see them we can give more intelligent advice.

Laszlo

How to post pictures

Oscar-Ronin my CV reads a lot like yours where 'glassing is discussed.

Stem & stern 'glassed fillets in the Waterlust I'm building reminded me that 'glass cloth is provided as a two-dimensional material but with some care and attention can be coaxed into conforming to three-dimensional shapes... kinda.

My experience building a Pumpkinseed stripper scow back in the early '70's introduced me to these arcane arts yet the years since saw much of those lessons learned gone a bit slack. Which 'glass cloth inherently isn't willing to do by itself. Divest yourself of any idea that its weight will help pull wrinkles out once it's dry-placed.

This Internet thing is a wonder, in that the experience of others can be spread about to the uninitiated with ease. Over at Off Center Harbor for instance there's an excellent video series on building stitch & glue watercraft. Segment #9 involves just this topic.

When I stumbled across it a few months ago it refreshed my recollections of what I probably did wrong on that scow when the 'glass and polyester met wood.

Last week, doing those 'glassed fillets in the 3D-curved & narrow ends of my Waterlust it quickly dawned on me that the only way I was gonna avoid having hard-cast wrinkles was to take smallish cuts along the 3" tape's edges once it'd been wet-out. Then the cuts could be overlapped, which adds thickness but avoids weakening the lamination as much as is possible with the doubled-up fibers solidly glued together beyond where the cuts begin.

Take Laszlo's advice and post pics here. Your current challenge may not be quite like mine. Seeing what you've confronted will help the rest of us relate to what it is you may wish to approach differently next time.

Thanks guys. So even pressed flat in the bag, you can see a crease in the cloth...

It's these vertical creases that are giving me problems

after epoxy has cured, you can see in the light that they're still raised. They initially seem to lay down flat with the plastic spreader, but they slowly lift back up again. This has another I think 2 coats of epoxy on top and it makes them less prominent, but I don't want this on the exterior.

OK, that's clearer.

There's typically 3 reasons why you get those kind of raised ridges. Either:

1. The glass takes a crease from the way it was packed and is not flattened during layup,

2. The glass is laid up on a surface with either a strong curve or a curve in two or more directions.

3. The builder was ham-fisted or careless.

In this case, it looks as if you have #1 going on. Once the glass is epoxied in place and it cures, the only way to fix the ridges is to remove the glass and try again. You can either grind/sand just the ridges and apply a new layer of cloth over the exposed wood, or use a heat gun to remove the entire sheet. It doesn't look to me as if it's worth all that trouble since what you have looks mostly cosmetic. If you can avoid the same problem on the outside of the boat, it'll be plenty strong even with the interior ridges.

The solutions to the problems above are:

1a. Buy your glass on a roll, if possible. That way it will never crease, Or:

1b, With clean gloves, keep smoothing the glass against the wood and working the threads into their new place. After the glass is on the wood, wait a few days before applying the epoxy for the glass fibers to relax and the creases to go away. If the glass is really creased hard this won't happen, so move on to:

1c. Fasten the glass in place to stretch it smooth, wait a few days for it to relax and then apply the epoxy while it's still being stretched over the wood. Cutting the glass large and using tape along the edges is a good way to stretch it.

2a. Apply the glass on the bias. That is, with the threads at a 45 degree angle to the direction of the major curve instead of 90 degrees. This may help the glass follow the curve batter and sit smoothly. If that doesn't help:

2b. Cut a dart. That is, cut along the top of the ridge and fold the glass so that one piece overlaps the other. (You're guaranteed to have to do this at the bow for a WD12.) If a dart doesn't fix it:

2c. Use several smaller pieces, possibly cut on the bias and with darts, instead of one large one. Each piece will have a less difficult curve to accommodate.

3. Be more careful and take your time.

1b and/or 1c should keep you out of trouble on the outside.

Good luck,

Laszlo

Laszlo's analysis is a thorough one. All good advice for dealing with what's depicted.

I have to wonder - given how CLC packages their kit-supplied fiberglass cloth (mine came folded, in a bag) - whether taking the time & trouble to unfold 'glass cloth then roll around a carpet-roll cardboard core or piece of PVC drain pipe (careful with that though over PVC pipe's notorious tendency for attracting dirt & dust!) might help flatten those creases?

My kit's cloth has been folded for three years almost... perhaps I'd be wise in choosing new over what was kit-suppied?

There's no problem using folded, instead of rolled, as long as you take the time to get rid of the creases. I've used folded for years without problems.

Rolls also have a disadvantage or two. They take up more space and weight when being shipped, so shipping costs are higher. They need extra plastic to be wrapped around them to stay clean, so there's more labor, weight, materials cost and pollution. They also require a core to be provided. Once they get to you, you have to find a place to store them and re-wrapping them is a pain. So there's lots of advantages to buying it folded in a bag. It's not necessarily a slam dunk to get a roll, even though it eliminates the need to deal with creases.

I'd have no hesitation at all in using the kit-supplied glass, even after 3 years (I've had some glass folded in a bag for over 10 years). Just plan to maybe have to deal with creases. That said, I buy mine on rolls whenever possible, but mainly because I buy bulk since I live close to CLC and shipping is not an issue.

BTW, CLC's policy on shipping on rolls:

Orders of 11 yards or more ship on a roll at no extra charge.  Smaller quantities of fabric may be rolled for an additional shipping & handling fee of $5.00.  Just add the Rolled Fiberglass item to your cart.

Laszlo

OK thanks for the added information!

Given the costs associated with buying more cloth I'll go the kit-supplied route when the time comes... which will be fairly soon, at least for the interior's bottom sections on my Waterlust project! 

We didn't have this exact problem on our PMD, as best I remember, but we did go around with squeegies (did I spell that right?  the plastic applicator thingies) as the epoxy began to cure to keep working the cloth down in any spot where, for whatever reason, it displayed a tendency to wrinkle or pull away.  Maybe the preventative for any such "cloth memory" issues is to keep working it out smooth until the epoxy has cured enough to hold it down?

.....Michael

���Thanks Lazlo. Greatly appreciate the help. I'll tape it and let it rest a bit before I epoxy. Thank you!