Best Epoxy damning material

[Raif Harik]

Hi, I have rough turned vase like thing. Really a flower pot. It has big void like a smiley face going almost half the circumference and about 3/16 wide. I know most people are thinking burn it. But I'm in too deep! I kind of like the challenge. Anyway I built up and insane damn around the fissure with hot glue. It's taken a while to do, has lots of holes, I'm finding and patching, and it's leaking on the inside too. More people saying burn it. I was wondering if anyone had a better damning material than hot glue? I figure once I've done this I"ll know a whollle lot about this sort of thing, so it's kind of fun.
I'll post a pic here in a few.
Anyway, Thanks,
R

 

[Robert Arnold]

Raif, there is some masking type tape that is very adhesive. The one I use is from 3M and is green. I’m sure here are others. I put tape across any voids I want to fill. Overlap each piece of tape about a quarter of its width and make sure it is secure. I use this method all the time.

 

[Brian Gustin]

I havent tried it yet but I have a completed bowl which the knot popped out of just as I was finishing sanding, with no real way to re-chuck it.. I have been trying to figure out a way to create a dam or form to match and maintain the curve of the bowl itself at least on the inside (I can re-turn the outside in my longworth chuck) so if I do think of something (Already considered plastic jug hot glued to inside, so far.. I am thinking I may instead fill the void with play-doh and then painter's tape the inside to match curve, then layer over a bit of fiberglass patch kit from auto body repair kit, once it cures, remove tape and play-doh and hot glue the fiberglass to the inside, then a very small mix of 5-minute epoxy around the edges of the void where it meets the form - just enough to seal it, then should be good enough to pour in the clear epoxy... maybe too complicated, but it's an experiment Im gonna try - one of these days.. OTOH, I might see about just filling the void, and hot glue the bottom to a waste block to re-turn the inside.... then do the outside in longworth chuck..

 

[Ray Ewing]

I have used aluminum tape successfully. does require a somewhat smooth but not perfect
surface to adhere to

 

[Raif Harik]

Here are some pictures to scare your grandkids with.
I learned from the side fix that you need high walls. I was glueing and mixing more epoxy alternately in a frenzy to try and salvage that repair.
I tested the hydrologic integrity of my muppet face fix before pouring the epoxy. Worked just fine.
I'll probably have to use a chainsaw to get this thing round again. Jk. I'll turn it with a big old scraper. Hopefully shouldn't be too bad.
If you never hear of this subject again from me, well you can assume either the pot or I am in pieces.
R

 

[Emiliano Achaval]

If I have something that big I would do at least 2 or even 3 pours. You are too ambitious trying to pour all in one pour here. In smaller sections, the dam is smaller and the hot glue works fine. That is just too big.

 

[Bill Boehme]

Epoxy putty is awfully expensive. I have successfully used Minwax Wood Filler to build a tall dam on a mesquite Canopic jar where I filled the void with clear Inlace resin. It took several pours and I needed to make sure that I had a tight seal between the wood and the dam.



The wood is honey mesquite, 16½" tall with numerous borer holes. Filled with Inlace resin.



Get the stuff in the squeeze tube because the stuff in the plastic tub would be too difficult to work with.

 

[Roger Wiegand]

I haven't used it in this particular application, but Plasticine would seem to be a perfect material for making temporary dams-- I've used it that way in the lab often. It's sticky enough to stay put on smooth surfaces, but peels off nicely when you're done. It makes a watertight seal.

 

[Lou Jacobs]

I was working on just such a bowl yesterday. I had success with masking tape just as Robert described. The two gaps on the outside of this blank are connected in one long “smile” on the inside of the bowl. I gouged out most of the bark inclusion. Then used MAS epoxy with fast hardener, filled with turquoise chips and dust. I found it was pretty runny, but I put the masking tape on the outside of the bowl, filled it from the inside, and kept the lathe turning at about 20 rpm to keep it from sagging to one end or the other, until it reached initial cure - about 20 minutes. I’ll finish turn today and see how it turns out. I’m a bit concerned that it is too much turquoise that will look garish. We’ll see.
Also curious, for those who use epoxy in this way, are you concerned about UV filter over the epoxy? I’m assuming it will need a varnish or similar finish for protection, though I usually like to finish my bowls with a utility oil finish.

 

[Raif Harik]

Sounds like plasticine would be the best choice. If it doesn't work I can use it to make a bowl instead! .
So I thought about multiple pours, especially when the side part was sub par. But I didn't know how well it would work. Like maybe there'd be a visible line or it wouldn't bond. Clearly I over thought it.
I trust I'll be able to turn all this epoxy off? I'm starting to get prep fatigue.
Thanks for all the great replies!
R

 

[Lou Jacobs]

My half-finished and finished bowl. I went ahead with the walnut oil and then wax finish. It will be a test to see if the epoxy degrades over time with UV exposure.

 

[Chris Lawrence]

Here is a video of how i did a small vase that had holes all the way through and rebuilding the rim.

View: https://youtu.be/n_57bgYcj38
I did a shallow pour in the through hole after i packed the inside to seal the hole and limit the amount of resin that filled inside the vase. I used transparency sheets to make pockets but any heavy plastic will work.

 

[Lou Jacobs]

A beautiful piece! I wonder if inserting a balloon and inflating it inside the form would work to limit the amount of resin that goes past the openings. Maybe a doubled up balloon (one inside the other) for extra strength.

 

[Chris Lawrence]

A beautiful piece! I wonder if inserting a balloon and inflating it inside the form would work to limit the amount of resin that goes past the openings. Maybe a doubled up balloon (one inside the other) for extra strength.

Thought about that but was unsure if the heat from the resin would pop the balloon. It worked out well i did a second tiny pour that i did not record. There was very little red resin in the bottom when i as done.

 

[Mike Johnson]

You could use a small diameter rubber inner tube the correct size instead of a balloon, I have used masking tape a number of times on the outer diameter of a bowl when needing to fill a void on a vessel wall. You make several complete wraps around the vessel which provides a good seal to contain the epoxy. A heat gun or torch will remove air bubbles from the epoxy if you apply
heat to the epoxy right after you pour it into the void, the heat causes the air bubble to rise out of the liquid epoxy.

 

[Bill Boehme]

Sounds like plasticine would be the best choice. If it doesn't work I can use it to make a bowl instead! .
So I thought about multiple pours, especially when the side part was sub par. But I didn't know how well it would work. Like maybe there'd be a visible line or it wouldn't bond. Clearly I over thought it.
I trust I'll be able to turn all this epoxy off? I'm starting to get prep fatigue.
Thanks for all the great replies!
R

Multiple pours shouldn't be a problem. I've done it with Inlace resin and epoxy.

 

[Clifton C]

Raif, I don't know if you've found these folks yet, I get stuck on their site every so often. I go to find one thing and end up down some other habit hole.

Home

Explore Epoxyworks for expert insights on epoxy applications in boat building, repairs, and various innovative projects.

www.epoxyworks.com

Looked up multiple pours and found this.

Bubble-Free Casting in Knotholes and Cracks

I will use large logs with huge voids to demonstrate the best practices for achieving a clear, bubble-free casting with 105 Resin/207 Special Clear Hardener

www.epoxyworks.com

 

[Dave Hulett]

useful thread. thanks for the tips!

 

[Raif Harik]

Hi, I mentioned that if you didn't hear back on this thread that the damming was a damn disaster and that I was probably in the looney bin. Well, the damming went fine. Too much work but it worked. In this picture, you can see some of the gap.
I am in the loony bin though so it wasn't a complete success.
R

 

[Breck Whitworth]

I use blue painters masking tape for most of my voids, but for a large area I agree with the 3M green masking tape. The balloon inside does work, but I would but a buffering layer of something between the balloon surface and the epoxy due to the heat. You could tape the inside then place a small layer of something over the tape to protect delicate balloon surface. Inner tube would work the best if it could be made to fit.

 

[Phil Winch]

I'd be very careful with inflating anything inside bowl/hollowform. Think about how heavy objects are raised using lifting bags. Our creations (especially those with voids and inclusions) are not the strongest vessels when pressured with expansion. A soft foam block/pad might provide enough force to stop leakage.

 

[John Hicks]

What about tuck tape?