I did an epoxy counter top for my van. It is poured over vynal flooring glued to 1/4" plywood. Epoxy only on top. In cold temps the countertop REALLY wants to cup into a U shape. Accidentally let it get freezing cold in the van and had to superheat my van to get the counter to lay flat again. Then I glued it with panel bond and screwed it down from the top. I did have it screwed down from underneath but when it got cold the counter bucked so hard that it popped off the screws. Might have avoided this issue by pouring an even amount of epoxy on the bottom if the counter as well.
No it’s not that case Totally disagree with this video he’s right about the overflowing with epoxy. My thing is when you pour make sure everything is clamped and leave it for at least 72 hours. Also, when you flatten your top, put it back on your table and clamp it it stay flat and leave it for another three days, and also the most important thing is if you can keep the same temperature in your room or in your shop
I poured 3 gallons of epoxy at once it cured to fast, heated up and cupped. I had to cut it all out and start over, I poured in 4 different batches to be safe probably could of done 2 pours but epoxy is expensive so I went on the safe side. I’m still learning.
I usually do add silicone to dam up the epoxy. I didn't on this one because I don't see enough of a difference between using the silicone and not using it. I mainly use the silicone to dam the epoxy around other voids in the slabs other than where the main river is. Either way there is going to be cupping unless you cover entire surface in epoxy which is what I've been doing lately. nice video explanation thought Brian.
Quick thought, If there's very little epoxy on the bottom more moisture could potentially get in causing the bottom to expand While the top is locked in with the epoxy. I used to put lots of finish on my table tops and bottoms to get a sealing equaLibrium for Potential moisture migration top and bottom Which can cause your table tops to Become concave.
I have just started making tables the overspill is thin and cures and shrinks quicker the deep pour cures a little slower and so is displaced as the top thin layer shrinks just an observation but you are right overspill is the main cause in my opinion from a physics point of view makes sense.
Great video. My 40” wide river table is cupping quite a bit. Is it possible to use some boards and clamp it, tightening over a few days to pull it flat? Then maybe reinforce the bottom with metal strips to lock it flat. Any suggestions ?? Much appreciated
Just made a large table, and had to leave some epoxy under the two ends of the piece to try and get a full 2 inch thickness, and that’s what the client preferred when given the choice knowing the risks. The result is an environment where the wood is contracting slightly, creating a subtle curve in the boards only where the epoxy covers the underside, preventing the wood from contracting in a balanced manner. Off by 1/4 inch when moisture in the air is low
I have poured a few table tops now and always overpour to make sure any cracks or voids get filled. Never had it cup from doing that, Im gonna guess is there is more moisture in the pieces than there should be. I had one that cupped on my after it was flattened, removing the excess epoxy and taking off some high spots. My pieces were flattened before I used them. I believe my problem is I found a higher moisture content in one area of the bigger, center slab, that I didnt notice before. I flipped it so the hump part is up and clamped it down, hoping it stays put after awhile.
I just bought my first slab to work with and the guy at the shop was doing exactly this with the CNC on some tops and he told me about the bead of caulk on the edge. I also thought it was for cleanliness, but this makes sense. So when they are making the river tables with epoxy covering the whole thing, how do they keep it flat? By doing the bottom first?
I think maybe when it is done as a separate poor on the top it’s not pulling on the sides of the wood like the river does when it shrinks, if the table has been pored and is already stable the river has already set in place without any stress on it and will hold any shrinkage caused by the top coat from developing ( just my thoughts) so we can assume that if you poor the river in the leased amount of pours possible, use a dam and maybe even after the firs layer of the river is poured and is set lift the centre of the table very slightly so as the second pour shrinks it will be pulling the slabs back into kilter
it makes a lot of sense. if you're not pouring a tack base on the bottom before you set the slabs in, and you pour the river and top of the table it is going to cup upwards on you. I am personally not a fan of epoxy covering the whole table; top or bottom. I believe the river should be epoxy and the wood slabs look the best with a hardwax oil finish. It is the closest to feeling the grain still and not a coating. thanks for the video.
How about milling one side at a time don’t clamp both sides just one, mill the epoxy off, then do the other side separately then this will allow the pulling of the epoxy to release, you can then clamp both sides. Why go to all this bother, well if you have a table that is so bad you will lose to much wood, or that you might crack the table when you pull it down with the clamps this will pre release the tension and reduce the amount of wood needed to get flat ( Just a thought ) good video
Just another observation and comment I made on a question do you guys think this holds any water? The comment asked about the top coat cupping the table I think maybe when it is done as a separate poor on the top it’s not pulling on the sides of the wood like the river does when it shrinks, if the table has been pored and is already stable the river has already set in place without any stress on it and will hold any shrinkage caused by the top coat from developing ( just my thoughts) so we can assume that if you poor the river in the leased amount of pours possible, use a dam and maybe even after the firs layer of the river is poured and is set lift the centre of the table very slightly so as the second pour shrinks it will be pulling the slabs back into kilter
if you pour a river try not to over pour ,but you do over pour all you have to do is set it in the sun on a level surface or in a very warm room and it will level itself
pour a 3.2mm pour first to avoid cupping, then place boards on top, i call this my set coat and it gives you a finished bottom
Ken Cheadle- Are you letting it setup then putting boards in? Are you sanding the set coat?
I did an epoxy counter top for my van. It is poured over vynal flooring glued to 1/4" plywood. Epoxy only on top. In cold temps the countertop REALLY wants to cup into a U shape. Accidentally let it get freezing cold in the van and had to superheat my van to get the counter to lay flat again. Then I glued it with panel bond and screwed it down from the top. I did have it screwed down from underneath but when it got cold the counter bucked so hard that it popped off the screws. Might have avoided this issue by pouring an even amount of epoxy on the bottom if the counter as well.
So in a nut shell, dont over fill because epoxy shrinks, pulling your table top to the center, cupping it.
I’m so glad that I watched this before I poured my first table. Thank you for the great advice
Great video. Makes a lot of sense about the over pour. Thanks for sharing. What are your thoughts about coating edges?
Very informative video , thanks . I agree with you about flattening slabs first and not wasting epoxy .
No it’s not that case Totally disagree with this video he’s right about the overflowing with epoxy. My thing is when you pour make sure everything is clamped and leave it for at least 72 hours. Also, when you flatten your top, put it back on your table and clamp it it stay flat and leave it for another three days, and also the most important thing is if you can keep the same temperature in your room or in your shop
I poured 3 gallons of epoxy at once it cured to fast, heated up and cupped. I had to cut it all out and start over, I poured in 4 different batches to be safe probably could of done 2 pours but epoxy is expensive so I went on the safe side. I’m still learning.
Parabéns vc é um mestre no quesito madeiristico um artista a ser aplaudido
Epoxy tables may bend ..if we release the mould before 8 days...
I usually do add silicone to dam up the epoxy. I didn't on this one because I don't see enough of a difference between using the silicone and not using it. I mainly use the silicone to dam the epoxy around other voids in the slabs other than where the main river is. Either way there is going to be cupping unless you cover entire surface in epoxy which is what I've been doing lately. nice video explanation thought Brian.
Omg, thank you. I had this issue just with charcuterie boards and was ready to give up thinking I just didn't have the skills to do these
Quick thought, If there's very little epoxy on the bottom more moisture could potentially get in causing the bottom to expand While the top is locked in with the epoxy. I used to put lots of finish on my table tops and bottoms to get a sealing equaLibrium for Potential moisture migration top and bottom Which can cause your table tops to Become concave.
I'd give a like to your video a thousand times each day if it were possible, man! Thanks a lot for the tips! It makes complete sense! Cheers!
I have just started making tables the overspill is thin and cures and shrinks quicker the deep pour cures a little slower and so is displaced as the top thin layer shrinks just an observation but you are right overspill is the main cause in my opinion from a physics point of view makes sense.
Great info. By the way, the spalted wood and the "natural" river resulted in a very unique and pleasing table top.
Very helpful advice - thanks for sharing. Cheers
Great video. My 40” wide river table is cupping quite a bit. Is it possible to use some boards and clamp it, tightening over a few days to pull it flat? Then maybe reinforce the bottom with metal strips to lock it flat. Any suggestions ?? Much appreciated
Ya thats ur best bet
About what does it cost to get a table flattened like that?
Thank you for this. It explains sooo much! I appreciate the share.
Great video and some really solid advice, thank you!
Just made a large table, and had to leave some epoxy under the two ends of the piece to try and get a full 2 inch thickness, and that’s what the client preferred when given the choice knowing the risks. The result is an environment where the wood is contracting slightly, creating a subtle curve in the boards only where the epoxy covers the underside, preventing the wood from contracting in a balanced manner. Off by 1/4 inch when moisture in the air is low
I have poured a few table tops now and always overpour to make sure any cracks or voids get filled. Never had it cup from doing that, Im gonna guess is there is more moisture in the pieces than there should be. I had one that cupped on my after it was flattened, removing the excess epoxy and taking off some high spots. My pieces were flattened before I used them. I believe my problem is I found a higher moisture content in one area of the bigger, center slab, that I didnt notice before. I flipped it so the hump part is up and clamped it down, hoping it stays put after awhile.
I just bought my first slab to work with and the guy at the shop was doing exactly this with the CNC on some tops and he told me about the bead of caulk on the edge. I also thought it was for cleanliness, but this makes sense. So when they are making the river tables with epoxy covering the whole thing, how do they keep it flat? By doing the bottom first?
I think maybe when it is done as a separate poor on the top it’s not pulling on the sides of the wood like the river does when it shrinks, if the table has been pored and is already stable the river has already set in place without any stress on it and will hold any shrinkage caused by the top coat from developing ( just my thoughts) so we can assume that if you poor the river in the leased amount of pours possible, use a dam and maybe even after the firs layer of the river is poured and is set lift the centre of the table very slightly so as the second pour shrinks it will be pulling the slabs back into kilter
Thanks for that information working on my first one for the wife
it makes a lot of sense. if you're not pouring a tack base on the bottom before you set the slabs in, and you pour the river and top of the table it is going to cup upwards on you. I am personally not a fan of epoxy covering the whole table; top or bottom. I believe the river should be epoxy and the wood slabs look the best with a hardwax oil finish. It is the closest to feeling the grain still and not a coating. thanks for the video.
CN you explain the clamping used here?
I’ve got to fix same
I should have waited, I could have been your thousandth!!
How about milling one side at a time don’t clamp both sides just one, mill the epoxy off, then do the other side separately then this will allow the pulling of the epoxy to release, you can then clamp both sides. Why go to all this bother, well if you have a table that is so bad you will lose to much wood, or that you might crack the table when you pull it down with the clamps this will pre release the tension and reduce the amount of wood needed to get flat ( Just a thought ) good video
Just another observation and comment I made on a question do you guys think this holds any water? The comment asked about the top coat cupping the table
I think maybe when it is done as a separate poor on the top it’s not pulling on the sides of the wood like the river does when it shrinks, if the table has been pored and is already stable the river has already set in place without any stress on it and will hold any shrinkage caused by the top coat from developing ( just my thoughts) so we can assume that if you poor the river in the leased amount of pours possible, use a dam and maybe even after the firs layer of the river is poured and is set lift the centre of the table very slightly so as the second pour shrinks it will be pulling the slabs back into kilter
Excellent advice. Many Thanks
If you cut into the epoxy then use epoxy to glue it back together to straighten the table. Will the cut line show in the epoxy?
The one you cut down the middlem was it down the epoxy?
Great information thanks
Easy prevention
Really good information!
What cnc bit do you use?
good advice.
Great advice
THX!!!
Thanks for the tip. Makes sense. I just thought that the dam was to prevent waste, but this explains a lot. Probably saved me a headache 🤕
if you pour a river try not to over pour ,but you do over pour all you have to do is set it in the sun on a level surface or in a very warm room and it will level itself