Colourfastness #1: A Little Experiment ...

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Blog entry by shipwright posted 11-26-2017 12:21 AM 1988 reads 0 times favorited 19 comments Add to Favorites Watch
no previous part Part 1 of Colourfastness series Part 2: One Month Check-in, .... some surprises »

All woodworkers know about and battle with the issue of colourfastness but in marquetry it is more than just a pest, it can absolutely ruin your work. All one needs do is look at the great marquetry created by the French masters of the seventeenth and eighteenth centuries, today mostly dull arrangements of subtly different shades of brown.

In an attempt to start to understand the factors at work in order to try to minimize their destruction, I am embarking on what I expect will become a series of experiments. This first one will look at the effect of sealing the raw wood off completely from the atmosphere with a thick coat of epoxy and the effect of a top rated ultra-violet filter in the form of ten coats of Epifanes Marine Varnish.

I am well aware of the fact that there is lots of research online but I just want to see for myself.

I started out by glueing several strips of veneer to a piece of plywood. Then after making some kerfs to separate the segments I applied four different finishes (and left one bare as a reference). The last coat of varnish went on yesterday so today the test began. Quite a simple test but I expect quite effective, the Arizona sun.

The finishes for this test are

1) Bare (Reference)
2) Shellac
3) Shellac with Varnish
4) Epoxy with Varnish
5) Epoxy

I am hoping to discover something (anything) that might help keep my work last a little longer. Who knows? Maybe I will.

Thanks for looking in. Discussion is encouraged.


-- Paul M ..............the early bird may get the worm but it’s the second mouse that gets the cheese!

19 comments so far

View Dark_Lightning's profile


4726 posts in 4273 days

#1 posted 11-26-2017 12:47 AM

It will be interesting to see what happens. Arizona in the winter is less harsh, as well you know. If you did this in the summer, the epoxy would melt, then char, and the wood would spontaneously combust in the heat. :p Where I live in California, it’s plenty hot, too. If placed in direct sun, you’ll get years of inside the Musée du Louvre UV radiation in a few weeks.

-- Steven.......Random Orbital Nailer

View drewpy's profile


1058 posts in 2521 days

#2 posted 11-26-2017 01:24 AM

This will be interesting to watch.

-- Drew -- "The greatest wealth is health".

View Longcase's profile


102 posts in 2611 days

#3 posted 11-26-2017 01:51 AM

Interesting Paul, where are you going to test your samples, indoor, outdoor, in shade or sunlight ?

View chippewafalls's profile


69 posts in 2479 days

#4 posted 11-26-2017 01:59 AM

Anxious to see the end results. Although we live in different climates, I have found over the years wood tends to lose its original color. A few years ago I started working with white oak more and less with exotic woods. Thanks for taking the time and sharing.

View Redoak49's profile


5328 posts in 3153 days

#5 posted 11-26-2017 02:00 AM

I will be watching as this also effects people who do Intarsia.

View sras's profile


6260 posts in 4293 days

#6 posted 11-26-2017 02:12 AM

Maybe set up a mirror to amplify the sunlight exposure?

-- Steve - Impatience is Expensive

View Druid's profile


2205 posts in 3959 days

#7 posted 11-26-2017 02:16 AM

Great project Paul, and I’ll be following with interest.

-- John, British Columbia, Canada

View Schwieb's profile


1917 posts in 4625 days

#8 posted 11-26-2017 02:20 AM

I’ve always had some understanding of what sunlight an UV radiation could do to wood shades. Sometimes positive and sometimes very detrimental. I will be watching with interest. Always been curious about claims of UV protection.

-- Dr. Ken, Florida - Durch harte arbeit werden Träume wahr.

View Joe Lyddon's profile

Joe Lyddon

10963 posts in 5216 days

#9 posted 11-26-2017 03:08 AM

Look like a NICE experiment!

How often are you going to take a picture of it?

You could setup a webcam and we could look at it all year around anytime we wanted… :)

This will be very interesting.

-- Have Fun! Joe Lyddon - Alta Loma, CA USA - Home: ... My Small Gallery:

View shipwright's profile


8734 posts in 3962 days

#10 posted 11-26-2017 03:55 AM

Thanks for the interest everyone.
To answer a few comments:
They are in the sun in my back garden in Green Valley Az. and yes, it is less intense than in the summer but I think that compared to the exposure that indoor furniture is likely to receive this should provide an accelerated degradation model. Not too scientific but real world “see it with your own eyes” evidence none the less.

I will take photos as time goes by over the winter while I’m here but not more frequently than weekly, more likely monthly.

-- Paul M ..............the early bird may get the worm but it’s the second mouse that gets the cheese!

View TungOil's profile


1384 posts in 1659 days

#11 posted 11-26-2017 04:44 AM

Should be interesting to see if the marine varnish really helps. Thanks for doing this experiment and posting!

-- The optimist says "the glass is half full". The pessimist says "the glass is half empty". The engineer says "the glass is twice as big as it needs to be"

View Boxguy's profile


2898 posts in 3432 days

#12 posted 11-26-2017 07:10 AM

Paul, looking forward to your results…keep the list.

-- Big Al in IN

View Sodabowski's profile


2400 posts in 3997 days

#13 posted 11-26-2017 11:52 AM

Paul, Shellac will change the colors due to its acidity, I worked with the guys at the C2RMF (Louvre, to make it short) on this very subject, actually we’re still working over this. From our research your best bet is Sandarac.

-- Thomas - there are no problems, there are only solutions.

View Porchfish's profile


862 posts in 3696 days

#14 posted 11-26-2017 01:10 PM

I’ve been playing with epoxies for a couple of years now, and have not seen the epoxy that does not carry a UV warning. everything from “PolyTek” to “Douglas and Sturgess” art house outlets for epoxies, Urethanes and Polyurethanes used in the in the casting & hybridization processes. Epoxies from “Stick-Fast” and S3, devcon etc are not 1st choices for casting, and seldom carry UV warnings . The poly-Tek folks recommend a top coat over any of their products with a marine Varnish for any works exposed to direct and indirect sunlight. I have an old friend who swears by CA glue overcoats, but he works in small scale. It will be interesting to see your results. Goodon’ya.

-- The pig caught under the fence is always the one doing all the squealing !

View kaerlighedsbamsen's profile


1363 posts in 2877 days

#15 posted 11-27-2017 04:50 PM

Love projects like this. Looking forward to follow your finds!

-- "Do or Do not. There is no try." - Yoda

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