Good points Andreas,
Health and safety working with resin.
Here's what I add into my PDF build logs for my resin models:
Below I have listed what I have found to be the primary differences for resin kits from plastic kits:
1. When resin kits are cast in their moulds, a release agent is applied to enable the cast resin parts to be more easily removed, which is similar to plastic kit moulding.
This release agent can leave a film on the surface of the kit parts, which, if not removed, can prevent paint or adhesives from adhering to the surfaces.
The easiest way to remove this film is to carefully and fully wash all of the model parts in warm soapy water, using an old, soft tooth brush, then rinse all of the parts thoroughly and leave to dry. Alternatively wipe the parts with Isopropyl alcohol (e.g. ‘Tamiya’ X20A thinners).
2. Resin, by its nature, is very brittle and can be damaged or broken easily, especially when handling small parts.
This is particularly evident when separating the individual items from the resin cast.
The best way to remove item is to cut them away with a razor saw, then clean them up afterwards.
Once removed from the resin cast, parts will normally have ’resin flash’ around or amongst parts, especially small items.
This is easily removed with a sharp scalpel blade. Heavier residue can be scraped, filed or sanded away.
4. Plastic kits are assembled using solvent adhesives, which melt the surface where it is applied and ’weld’ the joint together.
Resin however will not react to this type of adhesive and can really only be glued using CA adhesive or two part epoxy.
CA adhesive reacts to moisture in the air and on the surface to be joined. As most people know, it will also bond skin to whatever it touches, if the skin has CA adhesive on it.
Obviously extreme care needs to be exercised when assembling resin kits using CA adhesive.
5. Cutting, sanding and drilling resin will create swarf and more importantly, resin dust. The dust in particular is dangerous, especially if inhaled.
Therefore always vacuum the working area, and yourself, regularly. If you have a face mask or filtered respirator and find you can wear it whilst working, then do so.
Resin can easily be drilled or scraped, but remember how brittle resin is when it is being handled.
It is not unusual to find imperfections in resin cast parts, such as surface blemishes, small ’blow’ holes or ragged edges. This can be common on some resin kits.
These imperfections can be rectified by sanding/polishing and/or filling with modelling putty, then sanding/polishing.
6. Generally CA adhesive is supplied as ’instant bond’ adhesive, but there are some manufacturers, such as ’VMS Fleky’, that supply CA adhesive as standard, thin, slow and specific resin adhesive. Whichever adhesive is used you must ensure parts are correctly positioned and aligned before applying the adhesive.
Trying to separate mis-aligned parts once the adhesive sets will prove very difficult and may result in irreparable damage to the parts.
Mike
