home testing of your materials

[Ann and Neville Clement]

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!

[andy solywoda]

Excellent, Ann and Nev!

The price of quality materials is a small factor when compared with the investment of labor.

It seems that 1:2 epoxy ratios are more foolproof than the 1:5 type.

Ordinary white vinegar is very effective as clean up and minimizes allergic reaction.

Anti-blush epoxy is worth the extra cost.

 

[Rogerio Martin]

All my boat is 1:5  ...

andy solywoda said:

Excelente, Ann e Nev!

O preço de materiais de qualidade é um fator pequeno quando comparado com o investimento de trabalho.

Parece que 1:2 epóxi são mais à prova de falhas do que o tipo de 1:5.

Vinagre branco comum é muito eficaz como limpar e minimiza reação alérgica.

Anti rubor-epoxi vale a pena o custo extra.

 

[Ann and Neville Clement]

Peace was built with the epoxy recommended in the plans which had amine blush and we needed to wash that off each time we added another epoxy bond.  This was time consuming and Nev had terrible skin allergy reactions his skin specialist told him was caused by the amine.  Presently we are using an  epoxy without amine blush and it saves time and also Nev does not get the skin problems he had while we were building Peace.  I do not know if the 1:5 vs 1:2 ratio always is associated with amine or no amine blush, but maybe some of the other folks on this site will know.  I also do not know if MAS is the only amine free epoxy Nev would be safe with nor do I know if there are cheaper alternatives.  We are only building nesting/sailing dinghys these days so we are not using enough glue to need to worry about the expense so much and we do know he seems to be safe with the MAS, so we are not too interested in doing comparison testing on his sensitive skin.  We have helped some of the folks who bought plans from us fiberglassing their lower hulls and Nev did not react to the MAS.  To be on the safe side, I am the person who usually helps bigger projects with the glue and I leave Nev to help with carpentry, plumbing, and electrics. 

Everybody be safe with the epoxy.  Wear Nitrile gloves and not Latex which lets the amine through to your skin.  Wear a mask when sanding.  Don't breathe in the dusty additives you use to thicken the epoxy.  Check the pumps if you use them (we do) and shower each night after using epoxy just to be sure your skin gets anything caustic clmpletely washed off.  The glue has wonderful strength and it is truly magical stuff in the boat building method we use, but there are drawbacks and you can and should avoid skin problems too often associated with epoxy use. 

Here's to your health!  Ann

[Sami Rumpunen]

Glue test :

http://www.oldbrownglue.com/pdf/HowStrongisYourGlue_FWW.pdf

Sami

[Ann and Neville Clement]

It would be nice if James and Hanneke could comment on the above mentioned glue research and how it might or might not be useful with their designs.  I suspect they do follow what goes on in this website....   Are you there James?  Hanneke?   What are your thoughts?  

[Omar M. Rashash]

It's amazing what time and experience will do to your thought process.  When I originally read the FWW glue article, nothing about how they tested epoxy struck me as odd.  Looking back at it now, I realize they, as do most woodworkers, missed the point.  The majority of the benefits, and a lot of the strength of epoxy, comes from the use of additives.  In boatbuilding, unthickened epoxy is only used for pre-wetting and coating, not for gluing.  Unthickened epoxy, used as a glue, requires joints that approach the tightness of what is required for resorcinol glue, with most of the clamping pressure.

The "WEST" in West epoxy stands for Wet Epoxy Saturation Technique.  Unthickened epoxy penetrates the surface of the wood and the thickened epoxy, with the appropriate additives, provides the gap filling and joint strength needed.

[Robert]

An interesting thing to add to this is how repairable joints made with various types of glue are, see: http://www.sawmillcreek.org/showthread.php?21822-Are-Your-Glue-Join...

PVA is not waterproof or creep resistant, which renders it useless for boat building and even though some types are marketed as water resistant.

Though epoxy is not perfect, nothing has the all round performance and multitude of applications that epoxy does.  

I am use 3 types of epoxy for my Tiki 46; SP106 for coating, joints and fillets, Ampreg 21 for glass fibre work and S-Fair 600 for fairing.  The reason for all this complexity is labour saving, SP106 is well priced and does most things, but like the West 105/206 that it is similar to it is not great for wetting glass.  Ampreg 21 wets even thick biax very fast though it is more expensive than SP106. Lastly S-Fair 600 is very easy to use for fairing compared to mixing microballoons and epoxy, it is just so consistent and simple, it is also easy to sand.

Note that I am not affiliated with Gurit, that is what is available here and it works well for me.

R

[Robert Hughes]

Exactly right Omar.  The FWW article was written from the perspective of furniture makers and is of little or no relevance to our sort of boat building.  Long term water resistance is critical to us, and epoxy would win hands down on that.  Also our joints tend to be a bit more "gappy" than those in a finely built chair, and about the only adhesive that will cope with that is epoxy with the right additive powders.

I've used urea formaldehyde, resorcinol etc (glues like Aerolite, Cascamite, Cascaphen) on previous boats but none of them proved to be as reliable and easy to use as epoxy.

Omar M. Rashash said:

It's amazing what time and experience will do to your thought process.  When I originally read the FWW glue article, nothing about how they tested epoxy struck me as odd.  Looking back at it now, I realize they, as do most woodworkers, missed the point.  The majority of the benefits, and a lot of the strength of epoxy, comes from the use of additives.  In boatbuilding, unthickened epoxy is only used for pre-wetting and coating, not for gluing.  Unthickened epoxy, used as a glue, requires joints that approach the tightness of what is required for resorcinol glue, with most of the clamping pressure.

The "WEST" in West epoxy stands for Wet Epoxy Saturation Technique.  Unthickened epoxy penetrates the surface of the wood and the thickened epoxy, with the appropriate additives, provides the gap filling and joint strength needed.

[dennis schneider]

Hi Everyone, I would like to challenge the notion that we need to use epoxy glue  for joints in boatbuilding...I used resorcinol and WEST back in the 70s, when Wharram was still 'recommending' Aerolite, and when I tore my boat apart 15 yrs later I could see many failed joints(perhaps due to glueing up in an unheated barn in Northern Germany).Since the 80s I have worked as a yacht repairman and house builder. I still use epoxy (gel) glue(2 part) for a few applications, but have gone almost completely over to PL Premium construction adhesive (lg tube, $7 at HD  and Lowes), which works great, as long as you have normal clamping pressure. I also no longer use marine grade plywood; CDX is fine,because  I always sheathe the underwater areas in laminating epoxy and 17 oz biaxial cloth. I no longer sheathe the topside vertical surfaces with 6 oz cloth, use instead 3 coats of epoxy rolled on extra thin and sanded lightly between coats. Decks like underwater areas. Paint: latex directly on lightly sanded epoxy coated surfaces. Metal fittings: mild steel coated in epoxy or LeakStopper roofing patch goo. Surely Wharrams were designed back then for those who - like me and Ernie Wiesner - had to just pinch  out our building purchases from our "fun" money budget as we went along, and today, in 2014, the way to do it cheaply - but structurally sound - is as I have just outlined. My 46' liveaboard cat will cost me under $20k, fully rigged, using used sails and home built mast. Every recommendation I make here has been tested by years of repeated use.  I do not make epoxy fillets, because its too messy and expensive. Any place you could use such a fillet you could do it much easier using  a wood cleat and PL Premium.  Also, I do not coat the interior with epoxy. Thats unnecessary; even if you had water constantly in the bilge (which would indicate that you are ignoring the cause) a couple of coats of HD mismatch latex paint (at 1/3 the cost) will seal out moisture just fine..... dennis schneider 

[wakataitea]

we used only west system and this with the right pump system... all easy and never a wrong mix. we used on all surfaces "peelpy". http://www.ptm-w.com/index.asp?pgid=204

 it stops the resin to run down out of the glas to. really good stuff. you pull it of, sans a little bit and keep working. this saved us a lot of work and time...

 i am wondering why nobody is mentioning it here...???

about all this testing... yes, sometimes you have to do it but it makes you paranoid too... i guess that you should only buy from companies you trust.. of course, shit happens but i believe that we can not compare the importance of material strengths in a wharram with one on an aircraft...

hans

[laurent]

" Decks like underwater areas. Paint: latex directly on lightly sanded epoxy coated surfaces."

same for me Dennis , to renew the old paint : one coat époxy (17 € / liter ) UV resistant they said ? , sanding and two coat cheap exterior house ALKYD water solvant .  

[Ann and Neville Clement]

Hi All,

     On Peace IV, we have used oil based polyurethane porch and floor paint costing 25 dollars US a gallon.  Compared to the two part paint we put on when we built the boat, it is standing up well on the decks which see a lot of traffic with sandy feet from the beach and things offloaded from the dinghy and dragged around.  It is exterior paint and designed to withstand freezing and hot, direct sunlight.  We use Glidden and we get it at Home Depot.  We first fiberglass the little dinghys we build these days, then lightly sand, and then paint on the porch and deck paint and it seems to work ok for us.  The only thing as good is the Brightside paint we get at Defenders but it costs a lot more. 

     I like to use good materials because once a boat is built and it takes you out on the water, you are going to love that boat and want to keep it and go out on the water again and again.  It is better to go out on the water than to put the boat in the workshop and keep fixing it all the darn time because you did not do a good job building it in the first place. 

     Peace is 12 years old now and she has taken us over 50,000 miles across water in Europe and the Atlantic and up and down the US east coast.  We have  been renewing the paint on the pod, cockpit, decks, etc and so far, I have used about 1 table spoon of epoxy for repairs.  Do it right the first time, use well tested materials, check your work, and save a ton of repair work during the life of the boat.  Sailing is much more fun than repairing.

     Ann and Nev