Where to put a small epoxied piece while it dries?

I have a really dumb question, because I keep making different forms of the same dumb mistake. I have some small thing I need to epoxy. So I apply the epoxy, and put it down on something. Gravity does it's thing, the epoxy drips, or merely touches the surface, and once the epoxy sets, the piece is stuck to whatever surface it's resting on.

Most recently, my Skerry's mast step. I epoxied most of it, except the edges that would later be epoxied to the hull and frame. I rested it on a plastic tarp, and the next day I had to sand off the plastic that stuck to the bottom.

Being really clever, for the next coat I thought: let's avoid the plastic. I put the epoxied mast step on my canvas tarp. That binds MUCH more tightly, and I ended up destroying my mast step while trying to separate it from the canvas.

So my question is this: On what kind of surface do you rest a piece being epoxied to avoid these problems?

3 replies:

« Previous Post       List of Posts       Next Post »

RE: Where to put a small epoxied piece while it dries?

1)   Pretty much any flat surface that's been given a layer of plastic packaging tape. I've yet to have epoxy stick to anything with a layer of that on it.

Don't try using the same taped surface twice w/o renewing the tape though, whatever's on the tape acting as a release agent seems to work best for just one use. And don't buy the cheapest tape you can find, it's not the best for this purpose. I like 3M myself.

2)   Thin polyethylene sheet, like that sold everywhere for plastic drop cloths or vapor barrier behind drywall. The really thin stuff – like tissue paper, maybe 0.0015" thick – I'd avoid if only for its delicacy and tendency to blow away in the slightest breeze.

I like the 0.004" (4 mil) stuff myself. I go through a 10' wide by 50' roll about once a year. 6 mil is more durable, more costly and more money but just as effective.

3)   Wax paper's often suggested but it's not my favorite. It works but may leave wax behind or tears, then what'sstuck has to be picked off.

Less common is a sheet of Delrin, Nylon or HDPE. None of those bond well to epoxy and any drippage can be easily popped free once it's cured before the next use.

RE: Where to put a small epoxied piece while it dries?

+1 on suggestion #2. It's cheap, readily available and epoxy will not stick to it. As for the actual place to put the part, when I'm building the whole shop is pretty full, so I like to put it into the boat itself on a polyethylene sheet.

Pieces with holes can be hung from a rafter using nylon fishing line. Or you can srew in an eye or hook and tie any string or twine to that.



RE: Where to put a small epoxied piece while it dries?

   Here are some tricks that will work on many, but not all parts.

1- As previously noted, anything that you can hang by a wire can be hung up, and will usually allow you to do the whole part at once.  Getting the last few patches covered without getting too much epoxy on your gloves and working out the last finger prints while trying to keep the part from swinging too much can be a challenge, but you'll get it figured out.

2- Many parts, expecially flat pieces, can have all surfaces done at once.  Use scrap pywood or boards of appropirate size for various sized parts and pound 3 nails up through the board. You can use more than 3, but that creates extra pin-spots and the part rarely touches all 4 nails at the same time - that's geometry. But 4 nails can create a more stable platform if you think you need it for larger parts.  You can thus coat all sides and edges of the piece at one time. You do one coat flat with the part resting solidly on your plastic-covered work surface, then flip it over on top of your support.  You can then coat the other surface and the edges.  Just be carefull to hold the piece with your free hand and/or be carefull in how you apply pressure so that the piece doesn't tip/slip off of the support. Coatings shouldn't be so thick that you have many runs or drips at all, usually just at any odd edges or inside corners where you get a little too much epoxy.  When done, you have only 3 very minor pin-prick blemishes on one side of the piece, no concern at all if piece is getting sanded and subsequent coats, easily dealt with to sand away or whatever even if a final coat.

3- Even if you choose to do only one side, after you've coated the piece set it up on something - a couple of cups, some saran wrap covered sticks or pieces of scrap wood, etc..

And underneath all of your work, you always want some thick plastic as described by spclark. I also say avoid wax paper due to wax conatmination of parts.  Setting your mast step down on canvas??  Ouch!! Now that is a lesson you learned the hard way... 

« Previous Post     List of Posts     Next Post »

Please login or register to post a reply.