Penetrating Epoxy Tests

I was making some bread and cheeseboards for friends for christmas, written up here if you want to have a go yourself, when I noticed the little spots on the end grain of the wood.
I had only filled the carvings, which are perhaps 3mm wide and under 2mm deep with CPES from a disposable pipette to seal the timber against the coloured epoxy running through the grain. Much to my surprise this tiny (far less than 1ml in each letter) amount of Smiths Clear Penetrating Epoxy Sealer (CPES), Warm Weather in this instance, had run all the way to the end of the timber from every vertical bar in the text.

That was a distance of 2cm, which I found astonishing in new wood. I noticed this after I had left the breadboard aside to dry, so decided to do a little more penetrating epoxy testing on my last offcut of this worktop.

For my first of my penetrating epoxy tests, I routed a deep groove diagonally across the worktop offcut. It went from 1cm from the near edge to 8cm from the near edge down it’s length, and was approximately 1cm deep in a 19mm Beech Block Worktop.

The whole was placed in a tray on a towel in case of drips.

I used disposable pipettes to fill the channel. A ‘radio synchronised’ clock shows the current time. I find an old cooking pinger timer to remind me to go back to photograph my penetrating epoxy test on Beech worktop. Little did I know that I was to need the timer.

This is 5:51 PM. It’s the 14th December 2020

It’s 5:52. 5 or 10ml of WW CPES has been poured into our beech block.

If you look carefully you can see that some Warm Weather CPES has already penetrated to the end of the wood. It’s penetrated through 2 or 3cm within a minute! Clerly the egg timer isn’t going to be needed here.

It’s 5:53, and a decent close up to show how well the Clear Penetrating Epoxy Sealer has actually penetrated.

The wood has completely absorbed the Smiths CPES I observe. The channel needs topping up urgently. This epoxy penetration into new hardwood test is all happening rather faster than I imagined.

It’s 5:54 now, three minutes or less for the The Smiths Clear Penetrating Epoxy sealer to penetrate. Clearly it is running nicely through the Beech in this test now. The Smiths CPES has not penetrated some of the blocks on this beech block worksurface however. The red rings show why, these are the ends of the blocks in the worktop. The CPES will not penetrate through the glue lines holding the worktop together.

These results of this penetrating epoxy test are genuinely surprising to me.

It’s 5:59, after eight minutes of penetration the penetrating epoxy has saturated a full 7cm of one block. This shot is taken from the other side of the block to the previous shot.

The beautiful grain patterns appearing on top of the wood show it penetrating mainly down the grain, with far less across the grain penetration.

The two blocks to the right of the timer clearly highlighted this, where you can quite easily work out where the grain actually runs down the two blocks, and it’s not quite parallel to the block itself.

It’s 6:18 now. Under half an hour into our penetrating epoxy test and we can clearly see the following:

Most of the blocks are fully saturated unless stopped by a glue line.

The Penetrating Epoxy ran at least 8cm down the grain, but far less across it (Millimetres perhaps, not centimetres).

Some blocks are far more dense than others, and have absorbed less, although one in the middle has a defect (a crack) that the penetrating epoxy has found and filled very thoroughly.

The board has absorbed so much CPES that it is now clearly bowed. The bowing caused the small surface spills , as the CPES exited at the lower ends of the channel while I filled the middle.

It’s 11:42. Nearly six hours for the penetrating epoxy to soak in in this test on beech block.

I haven’t been keeping the channel filled – that would be impossible with the timber this bent, but it gives a decent indication of the amount of liquid consumed (around 65ml was consumed in this test).

The Beech Block is still straightening out, and the silly curvature is an effect of treating one half of the timber through the use of the routed channel, but I will post another photo of how it finally dries.

If someone tells you penetrating epoxies don’t work, ask them to try this test. They can use heated laminating epoxy, or laminating epoxy thinned with a solvent such as acetone. Ask them what effect heating has on cure time, and acetone has on bond strength too if they are really persistent. Better yet, suggest they do these penetrating epoxy tests themselves, and see which product they prefer.

The Beech Block smells noticeably of Smiths CPES for 2 full weeks. The block does not noticeably smell for the first time on the 1st January 2021. I am assuming that this is the finished state of this Beech Block.

Penetrating Epoxy saturated that new beech block block in just 30 minutes. However, it took 20,000 minutes for the solvents to migrate out fully.