Working with 3D prints
3D printed parts respond well to a light sanding to remove any slight imperfections from the printing process.
A flat bottom can be achieved by sticking a piece of sandpaper to a flat surface and then sanding the base of the print back and forth.
A thin coat of a plastic primer is recommended to promote good surface adhesion for the paint.
If the print is to be displayed in the “raw state” without paint its recommended to give the print a coat with a clear UV protective paint i.e Krylon uv resistant clear spray. This will protect the print against UV damage caused by long term exposure to sunlight. Incidentally if the print feels a little soft it can be left in the sun for a few minutes to further cure.
Working with resin Tip’s
Get some tools
First thing you will need is to get hold of a few basic tools to make your life easier. Most resin items will need a little finishing out of the mold as they generally have some casting imperfections. Best thing to get is a hobby scalpel from most hobby shops to remove the excess resin, the sharper the better.
The second invaluable item is a small sanding device, again these can be found from most good hobby stores and usually consist of a sand paper belt wrapped around a shaft.
Primer, paint doesnt tend to stick to bare resin that well. There are numerous types out there but I have found that an automotive grade primer/putty is a great basis to apply paint on.
While your at the auto store it pays to grab hold of some automotive sandpaper, the finer the better. Think 800/1200 grit (or finer) and your on the right track.
Preparing the resin
1st thing to do is to clean up casting marks, simply grab your scalpel and run it around the area you want to remove, simple.
2nd step is grab your sanding tool and smooth out any rough surfaces or edges.
3rd step grab some sand paper and give the whole item a quick rub down to promote adhesion with the primer.
4th step apply a fine coat of primer/hi fill, wait 5 minutes and apply a thicker coat. wait another 5 minutes and apply a heavier coat.
5th step, once the primer is dry get out your sand paper and give it a bit of a rub down to remove any excess roughness. For a final sand add a little water and rub with a 1200 grit paper, taking care not to rub through the primer.
Once complete you should have a nice flat surface to apply your paint.
Making tyres for the resin wheels
Producing a number of resin wheels left me with a problem, these wheels needed tyres. I tried out a rubber product that could be cast but it posed 2 problems, firstly it was hard and messy to use as it was quite a thick product and secondly it was too soft so large profile tyres would tend to squish when weight was put on them, so what to do?
A simple hack I found was use a tube from a push bike and cut it to suit.
Simply stretch the tyre over the rim with the cut section facing the rear of the rim and the over hang over the front of the rim. Then simply fold the front section back over the rim/tyre so you end up with a nice neat fold over the front face of the rim. The rear can then be trimmed as required and you have created a simple low profile tyre.