advice from someone who knows about west system epoxy

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gary3029

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Following advice from forum I am replacing my keel box. Have removed..(destroyed) my old lifting keel box...it was rotten...very! The new one is going to be built with longtivity in mind, yet able to service easily. Guy at yard advised to coat inside of box with west system epoxy. Would this advice be sound? Have looked at site for further info. What are the thought here as I have no experience with this product
Regards
 
I've used it a few times. but only small jobs on my wooden boat (sealing and bonding the coachroof and decks in small parts).
See website below for a more comprehensive guide

http://www.westsystem.com/webpages/userinfo/manual/

I have also used Eposeal as a primer first to prep the wood etc. Can send you a user guide/info sheet on that as well if required?

Cheers

Steve
 
Yes, Gary, the WEST website and books are very comprehensive. I have done many dinghies and a 26' yacht lifting keel that way. One thing that never seems to be mentioned is the damage caused to the inside of the box by the plate going up and down, particularly if it has picked up some gravel. This damage then lets water in to the ply. Not a bad idea to put on a thin layer of cloth with the epoxy (check clearance !) to reduce this. Be sure to use a cloth compatable with epoxy.
This is easier done before final assembly.
Ken
 
Well done for biting the bullet -''you know it makes sense''!
This is a job that you can do at home (its a box) thus you can control the dampness in the air and the temperature.15c or a bit above is perfect.
As you have not used epoxies before-WEST stands for wood epoxy saturation technique-you cut the wood pieces,clean off any greasy fingerprints with acetone(which incidentally is the cleaner solvent for wet epoxies when you spill it!) and roll/brush epoxy onto the wooden pieces and then stick em together using screws or a nail gun or nails .
Myself I would apply at least 3 coats to the inside faces of the box and all end grain.I would worry about the outside faces only once it is assembled and glued and cured...
Chandleries will have basic west leaflets(SP Systems is another favoured brand),though a Google search will list the how to books produced by West(the Gougeon Brothers)/try ebay.Basically you can apply coats 'wet on wet' but once cured you should sand and use an abrasive scotch pad to remove the sweaty 'amish' waxy bloom that appears on the surface,and then wash with water/washing up liquid and then rinse with fresh water any area that are to be recoated,eg the joints..Once dry,subsequent layers can be applied or the already-epoxied pieces can be glued together with epoxy mixed with a filler(eg colloidal silica) to a mayonnaise consistency,this will gap fill any voids in the glued joints...
Once you have made it (!) the new box can be rebedded to the kelson with sikaflex and bronze screws(brass ones have a limited life)
It would be great if you can get a book and practise first.You will need the correct pumps for dispensing the epoxy and hardener in the correct proportions( I often use the mini pumps,and top up the mini containers from a bulk buy of epoxy),a box of 100gloves (Screwfix on google)lots of throwaway brushes and plastic pots/cups from your local pound shop pr B+Q...and a small 100mm roller and some foam roller sleeves.

I am sure others will add loads that I have left out!
Good luck,take your time and dont mix up big batches of epoxy at first until you are confident enough to 'get it out of the pot ' and spread quickly and evenly across the wooden panels .
 
Instead of using pumps I find the easiest way is to mix by weight (which is possible with WEST system). Use a shallow plastic container and a set of electronic scales. It's a good idea not to make batches of any more than 200 grams otherwise it's likely to heat up quickly and either ruin itself or set faster than you can apply it. Epoxy doesn't bond to plastic so all you need to do is pick it out of the tub and it's ready for reuse.
 
Since you are building a new box, you have the opportunity to incorporate some improvements. One of the best improvements is to build it with a generous clearance between the centreplate and the side of the box. This clearance will ensure that the plate doesn't bind in the case. However, you need a good fit to ensure that the plate doesn't just flop all over the place, so you should fit two or three strips of hardwood vertically to the inside of both sides of the case. These will take the wear, and by having a smaller surface area, will provide less friction than the whole surface of the case. By all means coat the inside with a generous amount of epoxy, bearing in mind that you hope to never see this again. Incorporating a light glass fibre cloth will give some structure to support the epoxy. Pay partuicular attention to the end grain on the edges of the plywood, and anywhere else, for that matter. I use the International/Epiglass suite of epoxies, but that is just a preference. I have found that an old credit card makes a fine squeegee to spread the epoxy. A plastic picnic knife is also very good, as they usually have serrations which spread the epoxy out just beautifully, giving a nice, even coating. This can then be smoothed with the credit card. The Epiglass epoxies can be cleaned up [and this includes brushes] with plain old- fashioned vinegar. I'm not sure if the W.E.S.T. epoxies will be cleaned up with this or not. The dealer should be able to tell you.
Peter.
 
no matter how much you try to protect the inside of the centre plate box with epoxy or epoxy/glass, you are going to get the sides worn by the action of the plate going up and down.
a good method of avioding this is to make the box over size then epoxy or epoxy/glass the inside, when dry bed down a strip of delrin 2 or 3 inch wide on each side this will act as a bearing surface for the plate.
 
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