West System 407/410 filler

Discussion in 'Boat and Accessory Building' started by northvansteve, Jan 31, 2015.

  1. northvansteve

    northvansteve New Member

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    I picked up my supplies from Rod @ Orca Boats like some of you recommended. Pretty sure I took the 407/410 (can't remember which one) out of the package and thinking now I shouldn't have. I do have gaps in my strip kayak and want feedback on the use of these products. I'm going to cut my glass this weekend and play with the offcuts on the bulkheads, hip plates and backrest to get the hang of using the glass and epoxy. Probably going to dedicate next weekend to having a go at glassing the hull. If I'm using these products for filling then I assume this would have to be done ahead of time. Tips...advice...and yeah, probably should have listened to the expert..... :doh:
     
  2. Astoriadave

    Astoriadave Paddler

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    Here is the filler guide. Either 407 or 410 will work. 410 easier to sand. Just follow the mixing instructions, per second link, and fill voids with a spatula, putty knife, or a squeegee blade, leaving each void a little proud. Make small batches to avoid having one go off before you have used it up. Sand and or scrape flush, sanding parallel to the strips, using a sanding block. Save the ROS for later. Deeper voids may require a second pass of filler. I mix on a plywood scrap and distribute from that surface to minimize waste.

    The filler is easier to get the proportions right if you weigh stuff onto the ply scrap Instead of measuring out volumes. OTOH, if you can work quickly, a premix of the two components, followed by adding filler, will work just fine, per the WEST video, or the pdf, below.

    http://www.westsystem.com/ss/filler-selection-guide

    Download the pdf file describing the detailed steps for Fairing, here:
    http://www.westsystem.com/ss/fairing/


    Holler back when ready to glass. Lots of tips to make it easier.
     
  3. northvansteve

    northvansteve New Member

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    Will go with 410, I read it dries light tan...will blend better with the cedar. I'm a newbie to the glassing aspect of the build. Will prob have more questions along the way.....
     
  4. JohnAbercrombie

    JohnAbercrombie Paddler

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    Unless you have a lot of experience working with epoxy (like Dave does) I'd recommend using a non-absorbent container or surface for mixing epoxy. Mixing small volumes on wood or cardboard, you can have one of the components abosorb into the mixing board, throwing off the ratio. (Not a problem if the board has been epoxied/glassed already...)

    BTW, if you are using a (cheap) digital scale, make sure it isn't one that powers off automatically after a short 'inactive' period. It can really mess up your mixing! (Don't ask! :D )

    I'd advise doing some trials with the fillers - unless you have open 'holes' to fill, sometimes straight epoxy (if you are doing a seal coat) is less visible than filler....this is all assuming you are going for the 'wood-look' clear coat finish.
    I've used quite a bit of Microlight (410?) filler (under paint) and it is quite light in colour, even when cured. To my eye, dark lines between strips aren't as obvious as light-coloured ones, particularly if the filler doesn't run the length of the strip. If you have short (6" or less) gaps to fill, using wood shavings/strips can work well.
     
  5. Astoriadave

    Astoriadave Paddler

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    Northvansteve,

    There is quite a bit of tactile learning to both filling voids and glassing. Experiment on scraps before touching the hull, especially when ready to glass. A second pair of hands to mix resin and assist when something goes awry is really helpful when glassing. You will be fighting pot life of mixed resin all the way while glassing, for example, and you will need to learn how to determine when a batch of resin should NOT go on the hull.

    WEST has some good basic stuff on their web site to get you started.

    When you have done some experimenting, post back. You will have a better scan on what you need to know, then. A treatise on how to glass, at this point, would mainly be boring and pretty abstract.
     
  6. northvansteve

    northvansteve New Member

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    Today I'm practicing on the bulkheads etc. Determining the sweet spot in timing for when to apply the 2nd coat of epoxy is going to take a bit of practice. Even had some masking tape handy to compare. The tipping off has me confused a little. Some say on the fresh epoxy and some say before it gels. I have a 3" brush and now know that wasn't such a good idea as it now has epoxy in the bristles. Going to grab some acetone to see if I can save it. West says using half a foam roller and I see from some tutorials others using cheaper disposable foam brushes...? Am I applying the epoxy too thin that I can still see the weave on the second coat? Great advice from all!
     
  7. Astoriadave

    Astoriadave Paddler

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    1. Re tipping: buy a couple dozen disposable foam brushes, heavy on the 3 inchers, with a few 2 inch ones. That will get you started. Bristle brushes are useless, except for spreading resin on small jobs. And, uncleanable without great effort. Lacquer thinner cuts uncured resin better than acetone. Nothing cuts cured resin.

    2. Are you rolling the epoxy on? Better to lay out the complete batch of resin, ASAP after mixing. IOW, get it OUT of the mixing container, dribbling and pouring over the work area, then using the plastic squeegee to distribute it smoothly. Then wait a minute or so and use a bristle brush to ADD more resin to spots that have insufficient resin. Gently squeegee to even things out. Wait another 10 minutes or so, and hard squeegee into a wide waste container like a shoebox or similar, wiping the excess off into the waste container. This will leave a nubbly but clear layer of resin saturated glass on the work area. Rollers only work well on larger, flat surfaces. On a stripper, the squeegee technique is better.

    3. For fill coats, you should have a window of many hours before sanding would be required to achieve intercoat adhesion. Press on the curing resin soaked glass with a gloved finger, at hourly intervals. When there is some tack, but not enough to make the glove stick to the glass when you pull the finger away, you can apply the next coat. Again, the squeegee method is better for your situation, although a roller will even things out better. Most builders lay two fill coats, onto 6 oz glass. Sometimes three. On a stripper, half rollers are better. Buy a roller tool of the correct width.

    Remember, you MUST monitor pot life, and get the resin onto the work surface as quickly as possible after mixing. Everything, everything, everything else has to be ready to go. When the resin begins to set up, QUIT. Partially cured resin is thick and won't spread or saturate glass. It will only screw up the surface. Toss it.

    There is more to learn about managing temp when glassing. Post back when you feel confident about getting good wetting out of the glass.

    Finally, are you using fast hardener, medium, or slow? What is the temp of your work space during glass wet out? Do you have a way to control the temp easily, maybe a small electric space heater?
     
  8. JohnAbercrombie

    JohnAbercrombie Paddler

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    If the epoxy is cured, IMO the brush is trash. For 'general work' I use cheap chip brushes (from Industrial Plastics & Paint) but they shed bristles, so not optimum for finish coat work. I keep a large glass jar (large pickle jar) on the bench with a bit of acetone/lacquer thinner/alcohol - i.e. clean solvent disposal - in the bottom and store a couple of small brushes in there when I'm working. Depending on the jar size, I sometimes cut a bit off the handle end. However this is more for filleting and bonding work than for epoxy coating. For that, I mostly use a squeegee (auto body filler plastic rectangle - not the window-washing kind.
    I've never found a good use for the cheap foam brushes I've bought over the years. The WEST rollers do work well and the trick of cutting the roller and using a slotted stick for a handle does work, IME. They are expensive, but some of the 'look-alike' paint rollers fall apart with epoxy- having yellow foam bits in your finish coat is aggravating.
    IMO, multiple thin fill coats are better than trying for a glassy look in one 'go'.
    Asking the pros like Rod or Rob Macks or Dan Caouette (via kayakforum) will get you the best advice on clear coat techniques - they all do amazing work. I changed to painted finishes a few years ago, which makes some steps easier.
     
  9. northvansteve

    northvansteve New Member

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    Got that brush into some lacquer thinners....will see how that turns out. Will pick up some foam brushes and try those out before cutting up my west rollers.

    Using West 105 resin with 207 hardener and I am mixing small quantities and getting them on quickly and squeegeeing them out. My surface areas are small so that I can get the technique going.

    Current temp out there in garage is 19°c or 66°f. That's it for warmth, heater has been on since 7am. (had to pull the thermostat off the wall and take it out there..improvise!)

    Right now looking at the sheen of the pieces they look pretty rough with the weave showing. I know with extra coats filling that will smooth out. First coat was 9:30am, 2nd 11:15am

    Video tutorials online make it look soooo easy
     
  10. Astoriadave

    Astoriadave Paddler

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    Yeah, they lie ... or, they are experienced.

    The 105 / 207 system is a good one. 207 is a clear coat hardener. Not sure if it is equivalent to their fast hardener for speed or not. I am a System Three user. Others here will be more familiar with WEST.

    Check out their resources here, and I expect you may have already downloaded their manual: http://www.westsystem.com/ss/how-to-publications-2/

    That temp is OK for working epoxy. I have done a lot of work with fast S3 hardener at that temp. If the 207 is slower, it just means you will have more time to work the resin before it begins to cure, and you may find the resin is not fully cured in 12 to 16 hours. In lieu of moving the thermostat, you might want to dedicate a small electric space heater which you can turn on ahead of a work session, and turn off at the end. This will keep the temp cycling restricted to your work space.

    About temp management: wood is porous, and holds both air and water vapor in it. Wood held overnight at a temperature lower than the temperature of your shop when you are working resin will "outgas" both air and water vapor as you lay resin onto the wood, or are wetting out glass in warmer conditions. This can produce pinholes in the coating. For that reason, it is best to hold the wood for a few hours at a temperature a degree or so C higher than the temp when doing resin work. THEN, at the conclusion of working with resin, allow the temp to slowly fall a couple degrees C overnight. This temp decrease will cause the air and water vapor inside the wood to contract, pulling any liquid, uncured resin INTO the wood, sealing incipient pinholes.

    This sounds more involved than it is. Just use that small space heater to preheat your work area for a couple hours ahead of a resin session, and slack off on the heat when you begin work, so the temp does not rise much while working. Then, when finished, turn off the space heater or lower its setting to allow the temp to drop for several hours as the resin cures. After you have pushed your work space through a couple cycles like this, you will get the hang of it. For the bulkheads and other small stuff you are working on currently, temp control is not so important. But, when you get ready to glass the hull, it becomes critically important. Pinholes in the resin on the hull will lead to surface rot, as the boat gets wet while in the sun, and sucks moisture into the wood during use or on the beach overnight as it cools.
     
  11. northvansteve

    northvansteve New Member

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    All done for today out there. Current temp was 23°c or 73°f. Turned down the thermostat on the heater and will monitor this afternoon. I have a dehumidifier out there as well to keep the humidity down.

    At the start of all this I had the impression that I'd end up with a glossy surface from applying the epoxy. I'm guessing that will come with the next stage of sanding.

    Thanks for the pointers
     
  12. Astoriadave

    Astoriadave Paddler

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    Glad to help. You are getting a lot of info, fast, from me, because it sounds like you want to press ahead.

    For bulkheads and anything else not exposed to sun, bare epoxy is fine.

    On the hull exterior, the gloss of the resin will be removed after fill coats have buried the glass, using sanding. Then a protective finish is needed to keep UV off the epoxy. Are you planning to varnish it or what?