Working with resin: help needed please

[Mancunian airman]

Hi everybody

 

I was looking through a long lost stash  and came across a number of resin kits produced by 'Model Transport'.

I noticed that on a number of them the chassis isnt perfectly flat  . . .

I appreciate that there is evidence of flash then has to be removed . . .

 

A couple of question if I may . . .

 

I presume you would have to wash in soapy water to remove some form of molding  agent?

Do you use boiling water to straighten parts ? 

What is the best compound to fill in the odd 'bubble' ?

What type of glue is recommended  for resin ?

Is it advisable to undercoat before painting ? (I am still a brush painter)

 

Any other tips and advice would be welcomed to obtain the best results

 

many thanks 

Ian 

[AlxBNE]

I can't honestly help!....but you have asked a number of questions that I am keen to hear the brain trust's thoughts on.

My resin dilemmas are mostly due to resin conversion parts for aircraft but the techniques used are the same I am sure.....

.... looking forward to hearing what the more experienced modellers of BM have to say on the topic.

[Tegethoff]

Same as AlxBNE - many questions I'd like to hear the answer to. 

[Black Knight]

On 22/05/2023 at 09:50, Mancunian airman said:

I presume you would have to wash in soapy water to remove some form of molding  agent?

Best practice is to do so

 

On 22/05/2023 at 09:50, Mancunian airman said:

Do you use boiling water to straighten parts ? 

Some times you can. Clamp firmly between 2 metal plates to force the chassis flat. Pour boiling hot water directly on to the chassis, on all four sides then dunk in very cold water

 

On 22/05/2023 at 09:50, Mancunian airman said:

What is the best compound to fill in the odd 'bubble' ?

I use Revell Plasto for small air bubbles and UV light hardening resin for larger holes or to fill larger chips or joint gaps

 

On 22/05/2023 at 09:50, Mancunian airman said:

What type of glue is recommended  for resin ?

I use superglues, mainly the thicker gel type. I also use 'plastic soup' - aka 'sprue goo'

 

On 22/05/2023 at 09:50, Mancunian airman said:

Is it advisable to undercoat before painting ? (I am still a brush painter)

Yes, I think so. I always do. I use an enamel paint, usually matt black. I find acrylic paints won't take a grip on resin without a primer/undercoat

 

On 22/05/2023 at 09:50, Mancunian airman said:

Any other tips and advice would be welcomed to obtain the best results

Re-enforce joints with pins made from the steel wire of paper clips

Sometimes, use a very rough grade of grit paper to roughen up both faces of the parts to be joined. Gives the glue better grip on the parts

Don't use power tools on the resin without wearing a dust mask. Resin dust is bad for you. I wet cut or wet sand so the dust is carried away by the water

[dnl42]

Adding to @Black Knight's excellent advice.

 

I use hot, not quite boiling, water to straighten parts. You can immerse the parts or pour water over the parts depending on the specifics. In the example below, I held a wood clamping caul against the warped part and poured very hot water over the part until it softened and I was able to move it into position. It's important to keep the part in the new position until the resin cools and hardens.

 

Personally, I'm wary of CA with resin-resin joints whenever I need the bond to have any working time. I prefer 15 minute or even 24 hour epoxy in those cases.

 

I always clean all parts, resin, plastic, and metal with isopropyl alchohol before any painting. I airbrush thinned Mr.Surfacer as a primer; Mr.Metal Primer does a good job with metal.

 

[Black Knight]

I used to use Araldite type glues but I've found that new(er) versions of them never really harden and stay 'rubbery' for years. I used to use them on fletches on my arrows and the glue on the older arrows is much more solid whereas on the more recently fletched arrows the two-pack glue has never hardened. Thus I prefer to pin all joints and use gel type superglue on resin kits, and white metal kits as well. It gives a reasonable time for adjusting the fit of parts. But I/we/you should have worked on the parts before hand to make sure very little adjustment is required.