Epoxy pouring advice

Hello,

I have been looking up various resouces on epoxy and I found this video I thought I would share...

How to make an epoxy dam - YouTube

Talks about creating a dam to contain the epoxy and although his method (using tape) does not seem to lend itself to my use of leveling rails there were a couple of parts that interested me:-

• The guy states that epoxy will not bond with "blue" tape (is this the blue masking tape?) or duct tape. I wonder if this applies to all makes of epoxy? Could be useful to apply a strip of tape to whatever material you use to make your dam to allow it to release with ease?
  
• Priming - Making up a small batch of epoxy the day before the main pour and painting it on to seal any gaps.
  

This also got me thinking would the primed edge help reduce the meniscus forming?
Meniscus - Wikipedia, the free encyclopedia

Also, this one on avoiding surface imperfections when pouring:-
How to avoid surface imperfections in epoxy resin - YouTube

Cheers,
Jim

From my experience, epoxy won't stick the the non sticky side of duct tape. I think it will definitely stick to the sticky side. I wrap duct tape around wooden blocks and use them when clamping epoxy glue-ups, so they don't get stuck to the work.

Good video Jim.
I think he means blue masking tape. The priming idea looks to be worthwhile, I would most likely have used that method, I don't think it would have reduced the meniscus but anyway in practice it is so easily removed it's not worth fretting over.

Epoxy doesn't stick to the non sticky side of cellotape. Line any channel walls with that.

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Originally Posted by Ger21

From my experience, epoxy won't stick the the non sticky side of duct tape. I think it will definitely stick to the sticky side. I wrap duct tape around wooden blocks and use them when clamping epoxy glue-ups, so they don't get stuck to the work.

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Thanks for the tip! Odd thing is the guy in the video uses the blue tape with the sticky side against the epoxy. The way he describes it in the video makes me think this is also true for duct tape?
Attachment 11639

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Originally Posted by EddyCurrent

Good video Jim.
I think he means blue masking tape. The priming idea looks to be worthwhile, I would most likely have used that method, I don't think it would have reduced the meniscus but anyway in practice it is so easily removed it's not worth fretting over.

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I think I will use the priming idea when I come to it, seems like a good way to avoid leakages. I guess if the width of the epoxy is large enough it doesn't matter if the meniscus is removed or not?

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Originally Posted by CharlesJenkinson

Epoxy doesn't stick to the non sticky side of cellotape. Line any channel walls with that.

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Thanks Charles, good to know :thumsup:

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Originally Posted by cncJim

Thanks for the tip! Odd thing is the guy in the video uses the blue tape with the sticky side against the epoxy. The way he describes it in the video makes me think this is also true for duct tape?
Attachment 11639


I think I will use the priming idea when I come to it, seems like a good way to avoid leakages. I guess if the width of the epoxy is large enough it doesn't matter if the meniscus is removed or not?


Thanks Charles, good to know :thumsup:

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Nope it sticks to duct tape. Well mine did at least.

And you would want to remove it. After you take the tape off you can be left with some seriously sharp edges. Just get a sanding disk on a drill and go around all edges. Took me about an hour for about 18 meters worth of edge

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Originally Posted by cncJim

Thanks for the tip! Odd thing is the guy in the video uses the blue tape with the sticky side against the epoxy. The way he describes it in the video makes me think this is also true for duct tape?

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Jim, it's easy to do a small test first, you could use different tapes to find the best one, pvc electrical tape might be another option ?

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Originally Posted by cncJim

I guess if the width of the epoxy is large enough it doesn't matter if the meniscus is removed or not?

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That is true but honestly it only takes a few minutes to level it off with a good file, having said that I've had a lot of practice with a file.

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Originally Posted by EddyCurrent

Jim, it's easy to do a small test first, you could use different tapes to find the best one, pvc electrical tape might be another option ?

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Good idea, I will give this a go before attempting the rails.

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Originally Posted by EddyCurrent

That is true but honestly it only takes a few minutes to level it off with a good file, having said that I've had a lot of practice with a file.

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Well, you make it sound easy enough, I will need to buy a file first!!! :shame:

Is it just me or did that guy go a bit over kill on the epoxy for that pour, he must have made up enough to shoot the video a dozen times!

Anyway, as far as I know that blue tape is just a decent quality masking tape. Loads of the woodworking videos I've watched use it and they all refer to it as blue tape (in particular David Marks, he gets through a roll a show I reckon). I seem to remember seeing it for sale at ScrewFix a while back.

I used epoxy to fill knot holes in pieces of wood a few times and will usually make a dam with regular masking tape e.g. covering the back of a through knot so all the epoxy doesn't run out. The epoxy doesn't stick very well to the glue side of the masking tape but it's a long way from perfect. I always sand it down flush so I've never bothered to try and make it stick less. Talking about sanding it flush the best tool for this is a belt sander and that would be perfect for taking off the meniscus with the minimum of work too.

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Originally Posted by Wobblycogs

Talking about sanding it flush the best tool for this is a belt sander and that would be perfect for taking off the meniscus with the minimum of work too.

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It would be fine on a piece of wood as you described but if I had used my belt sander it would have completely knackered the epoxy job, too aggressive, can't see what's happening enough, not enough control on keeping it level. The file route is the only sensible way I'm sure.

That sounds like a challenge :-). The belt sander was a late addition to my tool selection so perhaps I'm still in the "how did I work without this" phase. I'd have the sander over at 45 deg to the poured surface so that only the meniscus was touched. Pretty sure you could easily control it enough then to avoid damaging where the rails will be fitted.

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Originally Posted by Wobblycogs

I'd have the sander over at 45 deg to the poured surface so that only the meniscus was touched. Pretty sure you could easily control it enough then to avoid damaging where the rails will be fitted.

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That sounds like a slightly better proposition but I tend to use hand tools a lot as I find control is better, material comes off slower, by the time I've got the power tool out etc. I've got the job done, it's good exercise.

I'd not trust myself with a belt sander...think I'll be going with hand files, plus I've just got myself a new set of files :whistle: