Glassing weave and temp?

So getting ready to glass the hull on my MC 13. My first build so a little intimidated. So two things  1-temperature  The experts get there shops up to 80 plus for low viscosity resin that flows on easier. That's great but the trade off of decreased working time for a newbie is my concern  

                         2- weave and wrinkles  Nick schade in his video recommends laying the cloth on a bias. Anything to watch for with this? I've laid the cloth ready to cut the excess. Brushed out the cloth dry removing the larger wrinkles but still noticing smaller ones I assume will  come out when wetted.???

Just that it all goes so smooth in the videos then there's reality for a newbie. 

So any tips or experience to share would be greatly appreciated. Happy holidays and stay well, thanks PP

P.S. waiting to do this till tomorrow expecting 5 or 10 more degrees from Mother Nature here. Working in a garage I can heat somewhat. 

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RE: Glassing weave and temp?

The epoxy certainly wets out better when it is warmer.  When it is cold out, I use an electric heater to warm the garage and also put the resin in a bucket of warm water before I start.  Mix smaller batches so that it does not kick off before you get it on the boat.  If you have not already, watch John Harris' video where he glasses a Chesapeake (Building a Chesapeake under the Tips for Builders Tab above).  Have fun - It will come out fine!


RE: Glassing weave and temp?

   You're right about the temperature. At 80 it might cure too quickly. At 60 - 80 I think you'd have enough time to work. At 50 - 60 it might take a very long time to cure . . . . Be patient. (These are my memories of the temperatures, but I'm not quoting from notes. Others might have more accurate numbers.)

Small wrinkle can be worked out as you are applying the epoxy. I first try to brush them out -- essentially stretching the cloth where I want it to go. A persistent bubble can sometimes be "drowned" in epoxy with a loaded brush hitting it from above. Once it is fully wetted and adhering to the hull, you can brush it out.

The most important tip is to mix small batches of epoxy and keep them in broad, shallow containers. Epoxy heats up as it cures and it cures faster as it heats up; sometimes a container of mixed epoxy can become too hot to hold! Keep it shallow so that the heat can disperse and everything will go more smoothly.

It's really pretty forgiving stuff. Don't worry. Every mistake can be fixed somehow.

RE: Glassing weave and temp?

a couple things i always keep top-of-mind when glassing a hull:

  • pick a point in the day at your target temperature range when the temps are either going to be steady or decreasing.  this is important to prevent outgassing and to also not have things accelerating during the session but holding steady or slowing.  my preference is the high 70s dropping ....
  • make sure you have all your tools organized and ready for the batches you will need.  the glassing requires multiple just have everything you need,...gloves, spreaders, enough measuirng cups, mixing items, a roll of paper towels, scissors etc.
  • if you don't want epoxy on your work area floor, make sure you have put down a plastic tarp or some kind of protection from drips.  this is the step where spills and drips happen on the floor.  you don't want to have to be over-worried about it.  if you know your floor is will not be distrated.
  • make sure to tell any house members you are going to be tied up for a couple hours.   turn off your cell phone.  you really do not want to get called away in the middle of this work
  •  if you are wearing a face mask (which i always do) sort out how you are going to prevent sweat and body moisture from dripping on the boat.   I wear a hat with a sweat brow, i often put a pieces of paper towel in my respirator to help sop up moisture....i try not to work when it is too hot.
  • think about how you will keep yourself clean and not contaminate your house with epoxy on your shoes or clothes.   for this step i usually  wear slip on shoes and have a little process to make sure i don't bring epoxy that may have spilled on my pants or shoes into the house.
  • after the mixing is done, get the mix out of the cup quickly and use the spreadher to move it will have time to work it if you get it out of the mixing cup.   i tend to work with relatively small batches. 
  • follow the guide to work from the middle of the boat out towards the ends.  it is disasterous trying to keep the cloth smooth if you don't follow this basic approach
  • after you are done, come back after every 10 to 15 minutes and just inspect to see if any bubbles or dry spots have developed.  these can be patted back down or a little more epoxy can help complete the wet out.
  • if something is not perfect, you can always fix it...relax and have fun.   

RE: Glassing weave and temp?

   I just finished glassing the deck of a Kaholo. It's mostly pretty easy compared to the skerry, because it's so flat, but still a few things to learn.  I started in the middle and worked my way out to try to the sides and end.  Mostly did ok.  The edges are where the cloth wanted to lift.  I had a bit more glass cloth overlap on the sides than the directions and I think it helps give a bit extra weight to help hold the cloth down.  I mostly use the squeegee but I used a chip brush on the edges and side.  I tap with the end of the brush to help push the cloth onto the edge, work out small bows in the cloth and drive epoxy into the weave.  I did get a lot of drips on the sides as the epoxy slowly moved under gravity.  I went back once with an alcohol rag to wipe away drips, but I didn't go back, and it kept going, so I have some sanding to do...oh well. 

The tap with the brush is a good way to make sure you have no dry spots anywhere.  Scissors were good to have at the corners of the stern/tailblock and the prow where I had to snip a little dart in the cloth and smooth the two bits over each other with my fingers and pat them down.  Even on the bias, there are always those points where you are converging the cloth on itself.

It would be nice to have a bit better idea going in how much I need to mix up for a given coverage.  I haven't gotten it right yet.  I made an initial batch of about 300 cc (24 pumps each) and it got 3/4 of the deck.  I did 3 more small batches of 72 cc to finish and do the sides and had just a bit left.  I don't know if this is more than necessary.  I have a few places where the weave is not showing much, but mostly is.  I don't think I floated the cloth anywhere, which I've done before.

RE: Glassing weave and temp?

Wow... 24 pumps x 2... you've got courage their my friend!

So far the biggest batch I've attempted has been 16 pumps x 2. A lot of what I've been mixing - at least before temps outside made temps closer to 65° inside more practical - has been with fast hardener.

I'm assembling in a heated garage mostly but even with that I've been reluctant to bring it up much over 62° for work sessions since I began 5+ months ago.

Letting it drop back to 55° overnight hasn't cost me too much. I chose fast hardener (or a 50/50 mix: a pump of fast then a pump of resin, then a pump of slow then another of resin) from the recommendations of the folks at MAS to avoid temps much under 59° using slow hardener alone. It's clear enough on their FAQ page that 50° isn't recommended for slow hardener mix alone.

So far I haven't had a batch click off before I could get it applied, nor have I had one fail to cure properly.

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