Thread: Machining epoxy

Hi Charleville,

Jointing or thicknessing boards glued with epoxy (Epi glue and Techniglue) will not in any way damage your blades.It's just not that hard when machined. I suspect you will not be successful in thicknessing material treated as you suggest: you will probably pull up a lot more breaks and gaps where you have applied the filler due to the new very strong intersects.

Unless you want the epoxy glue filler to be clear in color you can break it down with artists dry paint colors added as you are making up the mix. Put in as much as the glue will accept. Sanding is then relatively easy.

It's an absolute pain to do but it pays to mask accurately with masking tape the edges of every hole to be filled so there is no extra filler at all on the surface that doesn't need to be filled. I do this every time.

Also when sanding you have to take down the whole surface of the job to the new level that will signify the removal of all the surplus filler. Do this by applying pencil lines at about 25 mm intervals over the whole surface with a 2B pencil. Sand off all the lines and if necessary do the same again and again and again until the whole job is flat and planar.

I use a good quality ROS to do this function. Probably best to take the belt sander fishing and use it for bait and don't worry too much if you lose it.

The lazy mans way is to take the job to a joinery works with a wide belt sander and get them to discipline it with an old but still functional 100 or 125 grit belt. Best to go very gently say 0.1 or 0.2 mm per pass so as not to overheat the job as epoxy ( and just about all other families of glues available to the trade) is fairly thermo- plastic. Don't go to finer belts on the wide belt sander as they run hotter and if your job buggers the belt then there will be pain suffered.

Take it home and finish with an ROS to 400 grit after working up through all the intermediate grits; it only takes minutes with each grit. Happy sanding

Thanks Old Pete.

I never thought of using pencil lines in that way. Many thanks.



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On the subject of masking off accurately to avoid excess etc - depending on the imperfection I have found it worthwhile to punch holes in good quality masking tape using a wheel leather punch which gives a variety of hole sizes - for some of the larger imperfections larger single hole punches also work. [stick it down to a piece of clean scrap to punch the larger holes - not on the actual surface ]

Just a thought,

Regards,
Bob

Folks, thanks for all of your responses.

Based on what I have read above, my next bit of epoxy filled, birdseye timber will be passed through the thicknesser without concern. Many thanks for your advice.

However, my first projects with this timber and the filling of it with epoxy resin, were completed just before Christmas by sanding the surfaces only.

They are also displayed in the box making section but I thought it might be useful to show the outcomes here just to close the loop on this thread. The two document boxes have birdseye yellow stringybark on the top and front and rear sides and Queensland red cedar on the left and right sides. They were sanded down to 1500 grit and came out pretty damn nice to run one's fingers over.

Many thanks for your advice to my enquiry.


Click for large view - Uploaded with Skitch

Click for large view - Uploaded with Skitch


Clear epoxy was used in the voids, some of which are through holes. however, as seen below, the insides of the boxes are covered with felt so there is no visibility through the epoxy...


Click for large view - Uploaded with Skitch



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Turned out nice