Saturday, 29 June 2019

What I've learned about Grass Tree resin



Above is what I collected this morning.  I found a patch of bushland near my home which featured a few mature Grass Trees (by my estimation the species Xanthorrhoea drummondii).  Grass Trees are very familiar to anyone living in the Perth metropolitan area surrounds.  They are commonly found in suburban parks and are a common garden tree.  For those who don't know about Grass Trees go here:

https://en.wikipedia.org/wiki/Xanthorrhoea_drummondii

The resin balls vary in size from that of a pea to that of a small tennis ball.  If you want to collect Grass Tree resin the balls protrude from the exposed trunk and should break off easily.  If they don't snap of easily leave them as I'd hate to be encouraging people to damage the trees.  Snapping them off won't harm the tree.  Indeed Aboriginals have been collecting the resin in this way for thousands of years.  The resin had many uses such as melting and reducing it into a powerful adhesive.  However my intention is to use the resin for making varnish.  The stuff dissolves well in alcohol and is both a lovely natural red stain as well as a substitute for shellac.  However I will include shellac in my recipe.  This is the recipe that I currently use:

50g shellac (I like garnet shellac)
200ml alcohol
5g gum sandarac
50g Grass Tree resin
7ml eucalyptus oil

Violin makers would recognize this as a variation on the famous 1704 spirit varnish recipe.  I used eucalyptus oil instead of lavender spike oil to give it an Australian flavor.  The recipe flows out quite nicely with a good quality artist's brush.  It's definitely not as easy to brush as store-bought varnish, though.  It requires practice. 

Tomorrow I'll post some pics of guitar number 26 with the current progress on varnishing. 

Saturday, 15 June 2019

Number 39 as at 16th June 2019

I've been neglecting number 39.  This is a new design for me, taken from Graham MacDonald's book "The Mandolin Project".  The soundboard bracing is designed to resist any distortion of the soundboard than can occur over time to flat-top instruments.  The soundboard is Sitka Spruce, the back and sides are Western Australian She-oak, the neck is Phillipine Mahogany and the fingerboard is Jarrah.  The clothes pegs are for clamping on the linings while the glue dries.  More work to be done!




Saturday, 1 June 2019

Further adventure in varnish making


So today I walked down to my local park in suburban Perth to look for some mature Grass Trees.  Found a few and even, to my amazement, found three balls of resin at the base of one large tree.  I didn't expect to find this so easily as I expected that someone else would have been there before.  Grass Tree resin is an ingredient in incense and is used in aromatherapy I believe.  So I took my discoveries home and dissolved them in methylated spirits in a jar, added a little sandarac and tomorrow I will add some orange shellac to the mixture.  The orange should go well with the red/brown color of the Grass Tree resin.  Above is a short video of where I was at with it before dissolving the resin.