A Photo & Discussion Forum for Wharram Design Enthusiasts
When Nev and I bought ply for building our boat, we looked carefully at the laminations on the ply sample they gave us and then home tested it by boiling it for 20 minutes to see if it would delaminate. It passed that test and we were feeling secure until a few weeks later when we were gluing up the dry fitted lower hulls and discovered that the stuff we had tested and paid for was not what we got because our timber company had been hoodwinked by their supplier. We got a load of seconds and it was delaminating right there in the building shed. Also, we found overlaps, voids, and lots of places where the glue was missing or had gone off before the plys were pressed together in the bonding process. So it was obvious to us that testing needed to be something we did continually throughout our build. And our timber company was one of the best in Britain, so just going to he good guys does not keep your dream safe. You gotta continually protect yourself from nightmare materials. We were compensated for all the materials we had used so far, and also for our labor so far and the timber company switched suppliers immediately.
With marine ply, there should be no overlaps, there should be perfect glue adhesion between plys, and no voids. So look at the edges before you cut the pieces and then look at the edges of the pieces you cut too. Look for bulges in the top laminates as an indication of whether the laminate was properly bonded before the glue went off, etc. These bulges are seen easiest when you coat the ply with epoxy and can see light glinting off the wet surface. The timber company will take back any defective ply and replace it with the good ply you ordered and paid for. After our first mishap with the bad ply, we found only one more sheet that had a small defect right in the middle. They replaced it next day and I am glad it is not in the boat and that I know for sure that each and every ply sheet was perfect before it went into our boat. We planned a trans Atlantic right after launch, so I wanted total assurance we had a strong boat. After ten years and 48,000 miles, all our ply has stood up to time and been tested in ocean and coastal cruising and I am glad we were so careful.
When fiberglassing, I always worked carefully and did my best but that was not enough. I always came at it a couple of days later with a pair of pliars and tried to tear it off. Always it stayed put and the pliars came away with just a tiny bit of glass in the jaws and all of my work holding on tight just where I put it.
When doing coating or bonding, I mixed small batches of glue in old washed out tin cans that formerly contained the evaporated milk we like in our tea. These were nice because they were straight sided, free, and the squared end of the paint stirring sticks (cut down in size) fit perfectly in the squared bottom of the tin where bottom met side. I knew that each drop of resin had been mixed just right and no part of any resin had not been mixed thoroughly with its fare share of the hardener. After work, I always left that can beside the work I had finished leaving a tiny gob of the glue near the top and so I could test that it had gone off next day by trying to cut it with a knife.
When we built Peace, the plans were actually being drawn up as we built, so we knew there needed to be extra testing for the fillet sizes. I took a piece of scrap ply and bonded the edge of another piece of scrap ply to it at a 90 degree angle. Then I put a fillet of the suggested size and let the thing go off for three days to get proper strength. Then I crushed it in thevice and always it broke in the ply and not in my fillet. So I knew the the design was right and the fillet was stonger than the ply and that is surely strong enough.
From time to time, I hear of folks having troubles and I think that if you home test everything before and also during your build, you will be safe. The design is excellent for the home builder because it relies on triangles which are the most strong design. The cross beams are massively too strong which is excellent. Epoxy fillets are easy to do and they almost weld the wood together. Fiberglass is wonderful stuff. Put it on the way the directions say and it will work fine.
Nev has allergy to amine so we now use glues that have no amine blush and this protects us from another problem. Amine comes to the surface as the glue hardens and it is a water soluble stuff that looks like honey. If it is left there, the next glue will not stick properly to the surface of the first glue because the amine prevents good bonding. For example, if you are using coated ply, and amine is there, you gotta wash off the amine before you put the next layer of glue or fiberglass in place EVEN IF THE FIRST LAYER OF GLUE IS STILL " GREEN" MEANING A TINY BIT SOFT. Always you must sand any truly hardened glue before putting on fiberglass or adding another piece of wood using epoxy. The sanding creats a reliable surface for the glue to stick to. It will not stick properly to a shiney surface unless it is "green" in which case it will chemically bond and be super strong. We always preferred that but you gotta test to be sure it is still soft enough.
When in doubt, test and be sure. You do not want to be out there in a storm wondering about your bonding, fiberglass, and epoxy fillets, ply, etc. In a storm you just want to think about how clever Wharrams were in their design that was easy enough for you to build and be safe and happy in harbor after the storm. Then you can come home to tell the tale to friends who buy your beer just for the joy of listening. That actually happened to us a few times... free beer!
Post deleted. Never my intention to insult.
I'm sure that Galway didn't mean it that way. Galway speaks his mind which means that we are all occasionally offended. On the other hand he always has something on-topic and useful to say. Would you rather have polite but useless, or direct and useful - so few people speak their minds these days, that I personally find it refreshing.
Gosh, I had no idea "wannabe" was derogatory. Appology to anybody I ever said that cute sounding word to. But I do hope we can all join in friendship because we share the enthusiasm of sailing in the water with the wind and sun in good boats. Maybe we can overcome any hurt feelings and just share ideas and helpful information so we can get out and have fun, meet each other, and enjoy living.
Love, Ann and Nev
"Blessed are the peace makers". And best wishes to Boo and all boatbuilders. Phrases and humour - these things do not always translate across language / culture.
Very true. And humor is difficult in written text.
especially sarcasm. It is closely bound to mimic and tone. You either have to be face to face or know the other person VERY well.
I have made the mistake of forgetting this a few times :)
Well said Rune, I've got into trouble like that as well.
With such a diverse group of people misunderstandings will sometimes happen. The great thing about this forum is there's so much goodwill that it can almost always be sorted out and everyone can be friends. It really says something about the special sort of people who choose to sail Wharram cats. Love it !