Hi,
firstly thanks for the River table Video Tutorial and Demonstration you have on the product page (and on Vimeo) - easily the most helpful guide I've come across as I plan my first river table project.
I wonder if you could please help me out with a question I have from watching the tutorial:

At 5min 10sec in, Rich talks about clamping down the boards to take out any gentle curvature, and to stop the boards from floating on top of the resin.
Problem is the bottom of my boards curve quite a bit and planing the wood doesn't seem an option as too much would be lost. At just over 1 metre in length, the worst of the warping has a corner of one board sitting 6mm off the surface, and as seen in the photos I've added below there are other places where the wood rises and falls. 

I'm not sure if clamping down would suffice given the state of my wood? Also when unclamped won't the board revert to it's warped state and possibly damage the resin cast? 
From what Rich says in the video, it sounds like there would be a danger if I didn't clamp the boards down. So do I take it that simply placing my boards in a shallow bath of resin (base layer pour) and leaving to cure to the B stage ready for topping up is a bad idea?

Any tips as to how you would approach this, and what's possible with the resin would be much appreciated. 

Thanks,
Sam.

Top of boards:


Bottom of boards:

Hi Sam,

Thanks for the question.  As Rich said in the video, the clamping serves two purposes,  stopping the wood floating and straightening the board.  In yoiur case the main concern is the effect straightening may have on it warping afterwards etc.  YOu can limit the clamping to get a middle ground you are happy with meaning the wood is not under too much stress or literally just use the clamping to hold the wood in place, then relying on the resin to self level  where needed and working from there.

There is no right or wrong answer - you may well be happy with a bit of wood warpage even if it makes things a bit harder during the rest of the process.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Hi Warren,
thanks very much for your reply, it's good to know that I can go ahead and place the boards in the shallow bath of resin, then just lightly clamp down to keep things in place (rather than fully clamping to straighten).

To avoid any air bubbles would you say it's recommended to coat the underside of the boards in resin first, letting it fully cure, lightly sand, before I run the shallow bath of resin and place my boards in and lightly clamp? 

Also one other question if you don't mind - instead of using a large sheet of polypropylene for the base/sides, would wrapping baking paper around mdf work as a budget option?!

Thanks,
Sam.

If you are going to completely immerse the wood, then i would definitely seal the wood with some resin before you begin so that no air can come out of the wood.

I've not tried  baking paper with resin to see if it releases so you might have to test that one.  A cheaper alternative is polypropylene  flexible film/sheeting rather than rigid sheet.  You can usually get it cheap at builders merchants .


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

+x

 

SamJ - 3/21/2018 9:15:41 PM

Hi Warren,
thanks very much for your reply, it's good to know that I can go ahead and place the boards in the shallow bath of resin, then just lightly clamp down to keep things in place (rather than fully clamping to straighten).

To avoid any air bubbles would you say it's recommended to coat the underside of the boards in resin first, letting it fully cure, lightly sand, before I run the shallow bath of resin and place my boards in and lightly clamp? 

Also one other question if you don't mind - instead of using a large sheet of polypropylene for the base/sides, would wrapping baking paper around mdf work as a budget option?!

Thanks,
Sam.

Did you try the baking paper in the end Sam, and how did it go?

Cheers

+x

 

llyw - 4/2/2019 7:44:17 AM

+x

 

SamJ - 3/21/2018 9:15:41 PM

Hi Warren,
thanks very much for your reply, it's good to know that I can go ahead and place the boards in the shallow bath of resin, then just lightly clamp down to keep things in place (rather than fully clamping to straighten).

To avoid any air bubbles would you say it's recommended to coat the underside of the boards in resin first, letting it fully cure, lightly sand, before I run the shallow bath of resin and place my boards in and lightly clamp? 

Also one other question if you don't mind - instead of using a large sheet of polypropylene for the base/sides, would wrapping baking paper around mdf work as a budget option?!

Thanks,
Sam.

Did you try the baking paper in the end Sam, and how did it go?

Cheers

Hi, I didn't try the baking paper - instead I found a local(ish) supplier for the polypropylene sheet. Pieces cut to size and all set to use again and again.