> Anyway, I wound up not putting in enough hardner into the epoxy mixture.
> After a day of drying, the epoxy still wasn't hard - just barely starting
> to gel. I was able to pull the planks apart (I was gluing planks together
> into one 17.5 ft length). Using some denatured alcohol and a paint
> scraper, I got most of the epoxy layer off the planks.

> My question is - should I scrub down the glued area of the planks with
> alcohol again?

No

> Should I attempt to sand off the uncured epoxy (the epoxy
> application area is still tacky)? Or some other method to completely
> remove the original epoxy?

You can try sanding, at first it will be a mess, but once you get enough sawdust mixed into the glop it will eventualy come off. then you can go a bit deeper into good wood.

> Or, should I just reglue the planks using a proper epoxy mixture?

Eventually you will need to re-glue them, yes.

Ok now, some clarification. It sounds like there is no fiberglass involved here, just the epoxy resin used as a glue to hold planks together, in what I assume is an angular (scarf) joint.

Solve this problem in the simplest fashion: Cut a fresh edge and make a new joint. Use a saw or plane or power sander (don't bother trying to sand this by hand -- it would take way too long) and re cut the matching edges of your scarf joint 1/4 inch down. Do this on both pieces of wood that you are attempting to join. Your combined piece will be 1/2 inch shorter than what you started with. This should not be a problem.

If you use solvents they will only enable the uncured resin to soak deeper into the wood. This should nto be a problem as they will eventually polymerize into a compatible plastic, but it can be a mess, and the solvents are potentially more dangerous, and there is a definite cost involved. Physically removing the mess with a saw is the most cost effective and time effective method.

If you are ucertain of the accuracy of your mixing pumps, use disposable plastic drinking cups for measuring. I have seen a neat jig for calibrating them

Use translucent plastic cups. Most of these plastic cups stack neatly. Take a 4 ounce ( 1/2 cup) kitchen measuring cup and put exactly 4 ounces of water into one of your plastic cups. Use a permanent marker to indicate the water level in the cup. with the water stillin it, stack that plastic cup in a second one. Now mark the second cup in the general area of the water line on the first one. Take out the cup with the water, and cut a slot in the second cup. Cut right over your mark. this slotted cup is your jig. When you put a new plastic up into it, you just set yyour permanent marker in the slot, next to the mark for 4 ounces, and spin the new cup 1/4 turn to get a consistent mark on the outside showing a 4 ounce measure. If you are doing a 2 to 1 mix, make another jig for showing 8 ounces and a third for showing 2 ounces. Use these to mix any amount of resin you need. You may go through a lot of plastic cups, but 5o cups are going for about $1.50, so the cost is not that great.

If that pump is bad, call the dealer and exchange it. You paid good money for it and you should get something that works.

Always test your pumps. If you haven't used thigs for a while, just pump your resin and hardener into two separate containers and see if they are the proper volume. If not, add the required amount before you combine the contents of those two containers and mix it.

Hope this helps

Paul G. Jacobson