Greetings;
I’ve got some left over West Systems epoxy glue sitting around after another project. It’s still within it’s shelf life period and I’d like to use it up before having to dispose of it.
I’ve also get a few turnings (bowls and other hollow vessels) in rough-turned condition which, due to some unforseen knots and/or other hidden defects in the original blank, have resulted in some voids in the walls or bottoms.
I’ve seen some rather interesting pieces where similar ‘defects’ have been filled rather attractively with some sort of resin. Some colored, some clear, etc. The question here is, would it be possible to mix up a rather hot proportion of the west systems epoxy, tape on side of the vessel wall securely and use the epoxy to fill these voids? The resultant fill would have to be finish turned along with the rest of the vessel. How hard is the epoxy stuff on tools (all HSS turning gouges, etc.)?
Thanks for any comments/advice.
Replies
When I did that with West System epoxy, I was mostly using it colored with sanding dust, and I had a hard time with bubbles. If you want it to be bubble free, you need to mix it very gently, or maybe use a vacuum chamber to draw the bubbles out before you apply it.
I wouldn't worry at all about the tools. It's not very hard, in the amounts that you'll be running your tools through, I don't think it's abrasive enough to be a problem.
Interesting you should mention the bubbles, Unc'.
I'm putting together a handrail for my outside deck stairs. To connect the pitch change pieces to the main rails I decided to use what I call 'rail bolts'. Woodcraft calls them joint connectors but that's an academic issue I suppose.
These things consist of two wing shaped thingies that fit in holes drilled in the sides (or bottoms)of the pieces to be joined with small threaded rod between them, a nut shaped fitting on one end and a head on the other. They're meant to be used to draw two pieces together, mostly on the underside of countertops I guess.
*ANY* way, since this is an exterior application, after I got the first pair of rail bolts installed, I thought what I'd do is fill the entire cavity with something. So I reached for the West Systems, filled a paper cup about half full and stirred in a couple handfulls of sawdust. Then added a bunch of hardner.
Bubbles isn't really what I'd describe as the result (grin). More like foam the likes of gorrilla glue but not as expansive.
The whole process was done out in my cold (40+-) degree) garage shop wannabe. I really went whole hog on the catalyst due to the temperature but maybe overdid it a bit (grin). I always mix enough to leave some in the mixing vessel for testing cure progress and hardness. The garage was a few degrees warmer once that stuff started to kick off!!
Thanks for the reply. I don't think I'll use the sawdust filler for the fill in the bowls, though. I'm more interested in a clear filler approach. These are really practice pieces so I'll just .... practice. My biggest concern was how they would machine (turn).
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Dennis in Bellevue WA
[email protected]
Sounds exciting. I HATE exciting glue sessions!
IIRC, the West System literature firmly recommends against adjusting the resin / hardener ratio to compensate for temperature. Instead, they'd be happy to sell you special products designed for high or low temperature. :)
Well, another case of not experimenting first before final application.
The epoxy/sawdust combo didn't get hard overnight, even with a 60w bulb heater directly over it. Now I've got a firm but none the less jello filling round my joint connectors.
I've heard it said there *can* be too much of a good thing. Guess that goes with catalyst as well as chocolate.
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Dennis in Bellevue WA
[email protected]
I learned the hardway that the hardener should always be mixed BEFORE adding color or filler. That goop is going to stay goop.John O'Connell - JKO Handcrafted Woodworking
Life is tough. It's tougher if you're stupid - John Wayne
> .....That goop is going to stay goop.
Yeh, it's not getting any harder after close to 24 hours. It's about as hard as a firm neoprene rubber pad right now. Guess I should dig it out and try over.
Live and learn.
Will use casting resin on the next try, I think.
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Dennis in Bellevue WA
[email protected]
The bubbles you are getting likely are coming from "gassing" from the wood during rising temperatures; most of the manufacturers of this epoxy ( I use System Three for boat building) suggest using it when temps are falling. I am not sure I can explain the phenomina, but the epoxy seals the wood and as the temperature rises, the "gas" is sealed in and creates bubbles. You probably don't see it when you first apply the epoxy but it occurrs gradually later. Also, I have had difficulty matching the color with epoxy and sawdust or any other added medium. West makes some fillers (silica, etc.)but they tend to turn white or purple and just plain epoxy will darken the wood. As long as your project doesn't require matching color, epoxy is great but trying to get a match with it, is difficult.
I read "silica" as sand. That was/is out since I need to machine the vessels after the epoxy hardens.
I think this is a lost cause anyway since I don't seem to be able to get such a large fill to set up hard like casting resin - which is what I should be using in the first place.
Stupis is as stupid does (Forest Gump)
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Dennis in Bellevue WA
[email protected]
I use this stuff alot in rebuilding an old Boston Whaler.
The bubbles often come from mixing too aggressively. So use the slow hardener, not the fast hardener.
Don't use the silica filler, it is too hard to sand. Use either saw dust or their fairing filler. It sands much easier.
No matter what you do, unless your fairly lucky, you will get a bubble or two that reveals itself after sanding. This is particularly true in large gap filling uses. Just come back with a little more epoxy paste. It just means it is a two step process.
west system should work ok to fill voids, but dont mix a "hot" mix. Proportions of west system stuff is critical. if you need a faster setting epoxy use their faster catalyst
Dennis: I am going to guess that either you didn't have the right proportion or it wasn't mixed well enough. I have used gallons of West in the past and it is great stuff and it will work for your project. The pumps someone mentioned provide a perfect mixture.
Again, try West fairing additive. It comes in a white carboard can about the size of or maybe a bit smaller than Quaker oatmeal can. The fairing additive will leave a light tan color depending on how thick you mix it.
Typically, you should mix it to the consistency of peanut butter, particularly if you don't want it to slide. If you want it to self level, add less filler. Fairing filler sands very well. In fact, that is what it is for - building up and smoothing out fiberglass.
The only other thing to be careful of is how thick you put it on. Epoxy generates heat when it is mixed up in large batches. I've watched it smoke in the mixing cup more than once.
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