Cheap hardness tester for comparing hardness of wood-with-waterproof-coating

[Mike160304]

A great cheap amateur hobby is building ultralight CAR-TOP canoes/kayaks/dinghies etc with 3-5mm soft light okoume 3-ply plywood and relatively small amounts of liquid epoxy resin for glueing, taping seams, encapsulating and, sometimes, waterproof coating (e.g. 3 coats of epoxy soaked in and then protected from UV by almost any kind of paint).
Whether this is a hull or accessories, the hardness, for resistance to knocks, is important, but little discussed in "yotting" literature.
I like comparing finishes on tiny wood samples, for waterproofness - by soaking for 24 hours in water and then weighing the sample to check water absorption.
This is highly revealing, but also of interest is the hardness of the composite, before and after soaking, for resistance to knocks.
E.G. 7 coats of Rustins Danish Oil may be as waterproof as 3 coats of soaked-in epoxy, but how does the hardness compare?
For those of you still awake, my question is:
Is this cheap Shore A hardness tester likely to help me with this amateur experimentation? :

https://www.aliexpress.com/item/1576446608.html?spm=a2g0o.productlist.main.9.4b9b10b83j4xil&algo_pvid=c561ee45-f580-4e4c-bead-287be0b50e51&aem_p4p_detail=2024091402175211157833366231760012699448&algo_exp_id=c561ee45-f580-4e4c-bead-287be0b50e51-4&pdp_npi=4@dis!GBP!29.71!21.69!!!37.90!27.67!@210385db17263054729027539e2f6f!12000036655892678!sea!UK!0!ABX&curPageLogUid=dAsycrJ0gYDn&utparam-url=scene:search|query_from:&search_p4p_id=2024091402175211157833366231760012699448_5

It says that "Shore A" is for softer materials up to "resins", not for metals like Rockwell testers - and Okoume plywood is very soft when bare.
At this level of expenditure, it might be worth a go?
Mike

 

[ChaiLatte]

Look up the typical hardness for various wood species (the US and Europeans are big on wood construction). That would tell you if the gauge's reading range is in the same field as the (untreated) material you are using.

 

[Mike160304]

Look up the typical hardness for various wood species (the US and Europeans are big on wood construction). That would tell you if the gauge's reading range is in the same field as the (untreated) material you are using.

Yes, I have found wood hardness values in "janka", but there are a lot of references to using a Shore Durometer Type D for wood. The Shore A durometer is for softer materials, so I had found the wrong thing.
I'll look at Shore D Durometers.
Thanks,
Mike

 

[Spectric]

If you are looking for relative figures and not actual data then just make yourself one. All it needs is some object that can drop onto your sample from a fixed height and you just measure the indentation, or a more heavy object that you place onto the sample to see the size of the indentation for comparison.

 

[Mike160304]

If you are looking for relative figures and not actual data then just make yourself one. All it needs is some object that can drop onto your sample from a fixed height and you just measure the indentation, or a more heavy object that you place onto the sample to see the size of the indentation for comparison.

Thank you, I can understand how that might work well.
Mike

 

[Mike160304]

Well, this thread took me into some interesting reading and videos. One article said that I could create my own wood hardness tester by dropping a Robertson No. 2 screwdriver onto the wood from a height of 1.5 meters and measure the depth of the hole it makes.
But it makes quite a square hole rather than a pin-prick, a Robertson screwdriver seems to cost about £15 and I have no other use for one.
I could do the same-ish by reshaping the sharp end of a 6" nail into a flat point, taping say 3 more 6" nails round it and dropping it down a tube from a set height. The hole made would be just wide enough for the probe on my dial caliper.
But a nice man in a video said that he happily uses a cheap Shore D Durometer for all his woods, so I took a punt on this and it should be here in 7 days:
https://www.aliexpress.com/item/328...o.order_list.order_list_main.5.69601802I1AE7n
I have ordered the D version, not the A or O and at £14.87 landed it is about as much as I was thinking of spending, for my hobby use.
Mike