epoxy getting old

[DanaDCole]

My kit arrived in late December of 2013, so the epoxy is now over a year old. Officially, it is only supposed to last for one year, but I read somewhere that the resin is OK for two years, but the hardener is only good for one year. MAS is no longer responding to any of my inquiries. I guess I wore them out.

I had hoped to get the boat on the water by this summer, but I am just starting on the floorboards and reading ahead, I'll be lucky if I can get the hull flipped by then. So the resin and hardener will be getting close to two years old before I finish with them.

Any thoughts on this? I have almost finished the first five-jallon jug of resin. Should I throw out both the remaining resin and hardener, or take a chance with the resin I have and just buy new hardener? I am thinking I should purchase new resin and hardener because, though expensive, nowhere near as expensive as a ruined boat!

[Shudoman]

My PocketShip took three years to build and I used the kits epoxy for the entire project and have been using the left over in the six months since. I think the shelf life depends a lot on how it's stored. I live in FL and the epoxy is in my garage that stays pretty warm all the time. I have gotten sensitive to how old it is. Before each session where I use it I mix a small test batch. So far, so good. Your mileage may vary.

Bill

[DanaDCole]

Encouraging for sure, but in the back-and-forth posts on curing temperature recently John was quite adamant about things seeming to cure OK, but not holding up to stress tests. Are you sure your structures using older epoxy are strong enough--that is, have you done enough sailing in rough conditions and trailering over bad roads? I'm sure you have, but I'd like to hear your thoughts on that. I'm also sure after the earlier curing posts that epoxy companies are more interested in profit than absolutely accurate information--but on the other hand you can't blame them for being careful and conservative in their estimates.

Perhaps CLC should send the epoxy at intervals, e.g., half with the kit and half a year later. Faster builders could request an earlier shipment.

[craig]

I've seen people post on CLC's forum about finishing 10-year builds, presumably with the same epoxy. I'm sure it's fine. I'll pay for shipping if you want to send you old batch to my house though haha

I'll bet you can get it done by the end of summer, at least. The finishing part is the longest. I hate painting.

[Shudoman]

After 6 months of trailering and sailing I've experienced only one bad epoxy joint. About a month ago I noticed a crack on the rear of the seat back combing cap just aft of where the boom support exits on the port side.

The crack was about 3" long and probably around 1/32" thick. I'm not sure that the epoxy let loose. I'm more of the idea that I just didn't get a good coverage in that area. It was easy to fix. Interestingly that joint was done in the first year of the life of my epoxy stash.

I've read somewhere that cold temperatures can reduce the shelf life. Again, not really a problem here in FL.

Bill

[DanaDCole]

Thanks guys, this has been a great help and I feel much better.

As to storing the epoxy too cold, I don't know about it reducing shelf life, but I did learn the hard way that it can cause crystallization. I was storing it in my garage last winter and noticed a line had formed part way up in the resin--below that line it appeared "milky." I wrote MAS (they were still replying to me then) and they said not to worry, that I could fix it. They told me to place the whole resin container in a larger container of hot water for a few hours. This I did and that fixed the problem. I now store the resin and hardener inside the house. In fact the second container I haven't started using yet is sitting nearby and I can see it still looks fine.

So definitely the stuff should be stored at around 70 degrees or higher.

[DanaDCole]

In response to a comment in Shudoman's post, "I hate painting." I actually enjoy it, especially when using Interlux Brightsides and finding out I can make it look almost like a sprayed finish using a roller and tipping off. I could never quite get rid of the lap lines, though--the problem was the paint dries a little too fast. The lap lines are almost invisible on my kayak and Skerry, but I think they would be all too obvious on the sides of a PocketShip.

So, I decided to try spraying. Rockler had a sale on the Graco TrueCoat Pro II, so I took a chance and ordered one. I have almost no experience with spray painting, but I did some practicing on scraps, and then went ahead and used it to repaint the hull on my Skerry. I could not believe the results! I have no spray booth--just a garage. I made sure there was very little dust in the air and no bugs flying around (so this has to be done in the colder months). I extremely happy with how well it came out--looked like a car finish.

Well, with one small exception that is, and due only to my inexperience. I was getting ready to paint the last section, near the stern on the upper panel (you paint from high to low, but the hull was upside down). I had just filled the sprayer reservoir and I decided I might get a better pattern with a little increase in pressure. So I raised it a couple notches and it seemed to work fine while I was spraying. As the paint started to dry, I noticed two or three small sags--oh no! What I had not thought of was that the increase in pressure also increased the paint flow--so I was getting it on too thick. As it turned out though, the sags were are close to the rub rail and are small and very hard to see. Since I was almost out of paint I decided to leave them as is rather than sand and re-paint. Now that the boat is right-side-up the sags are hard to find and almost impossible to see--so I'm OK with them. Lesson learned, always use the lowest pressure you can (just like it says in the instruction manual). With Interlux Brightsides, the pressure setting to use is number one with this sprayer.

I don't believe this forum is the place to advertise products, but as I say I was very impressed with the Graco. I'm sure there are other brands that work just as well. Airless paint spraying technology has come a long, long way since my old Wagner I bought back in the '70s. I'd use it for the outside of a house, but that's about it. (And it's way, way noisier than the Graco.)

[craig]

Dana, sounds like a nice system. I've not had the best luck with the rolling-and-tipping method. Not sure what the problem is, but when I roll on the paint and tip it off, the paint sort-of "beads" up to form a non-smooth film. It doesn't fully bead up, where there are droplets. Rather, there are just high and low points. Anyway, I never could figure out what the trouble was and gave up. Painting is a lot of work with a narrow window to achieve success. Don't like it! haha

[Shudoman]

Yep as mentioned I do hate painting. The problem is that no matter how hard I try, how precise I am at masking, how hard I try to control the dust, insects, humidity, I never seem to get it right. I painted the outside hull using an Erlex HVLP sprayer and WR-LPU paint, 4 coats color, 2 gloss. The equipment and paint worked flawlessly. The operator, well not so much. Despite all my best intentions I still had some sags that needed touching up (sanding that paint is like sanding stones). Interestingly I switched to roll and tip for the interior and cabin top. That came out perfectly, and I do mean perfect. It looks like gloss gel-coat without a hint of brush strokes.

The lesson learned here for me is to leave the spray stuff to the experts and concentrate on my roll and tip techniques.

Bill

[DanaDCole]

Odd, I had the opposite results. As I said the roll and tip method came out really, really well but you could still find the lap lines (although hard to see) because the paint became tacky before I could get to the next section. I'm by no means an expert at spraying (total neophyte) but as I said it came out perfectly on the Skerry hull except for the very last part where I stupidly decided to turn up the pressure a couple notches. That resulted in a big increase in paint volume and some sags because it went on too thick. Again, the sags are hard to find, especially since they are hidden by the rub rail, so I decided not to order more paint just to redo that small section. Other than that, the finish looks like a new car body.

I guess the bottom line is "whatever works." The roll and tip method works best for some people and spraying for others. One advantage of spraying, though, is that it goes really fast. Other than that, to each is own.

(Maybe I was just looking for a chance to crow about my spraying job. )