Help needed Abs slurry

[Mh1986 9]

Hi, I'm very new to modifying plastic hard bodies and I'm currently struggling to make a decent abs slurry for filling gaps and reinforcing joints. I'm trying to stretch a grasshopper body to fit a DT03 chassis. I've tried using 25g part sprues in 50ml of acetone and ended up with a PVA type liquid with lumps that don't dissolve. I tried again yesterday same quantities but with new styrene sheet and ended up with a putty like blob sat underneath the acetone. Any advice would be much appreciated 

[Badcrumble 3703]

For ABS, I believe MEK is recommended. It has a similar chemical make up to Acetone

UK eBay link

 

[Mh1986 9]

Thank you, I'm not sure if my ratio is wrong

[alvinlwh 4116]

Em, 2 part epoxy?

[ad456 210]

I’d say it is a bit wet. Throw more plastic in or take out some of your liquid. You’ve got the right idea going I think. 
Hopefully someone with more experience will weigh in. 

This is what happened when I tried with acetone, I wonder if actual MEK or PlastiWeld would give better results but in fairness when I used it it was fine. 

Edited May 9 by ad456

[Mh1986 9]

If it was too wet would it not be really thin? If I try to stir it, it moves around like a blob in  the liquid it doesn't seem to want to mix. Would replacing the acetone make any difference?

[ad456 210]

You can just use the softened ABS as glue, that’s what I did and it stuck well when I tested it on other leftover sprues. 
I’m not certain it will mix “properly” when using acetone, this is probably due to my inexperience/lack of knowledge. 

[Mh1986 9]

Thanks for the advice everyone, it looks so simple on YouTube. I will test it on some scraps first.

[Mh1986 9]

Made a third batch, same quantities, this time only using tamiya part sprues, no styrene sheet and it works perfectly. Next question, can any one recommend a filler that will work with the abs. I just want a fine skim over the top to smooth out the imperfections 

[ad456 210]

I wonder if the sheets are a different type of styrene as the sprues as I used sheet too. 

[alvinlwh 4116]

6 hours ago, Mh1986 said:

filler that will work with the abs

Milliput.

[Busdriver 5499]

On 5/14/2023 at 9:57 PM, alvinlwh said:

Milliput.

Isopon P38 two part filler. Use on 1:1 cars but can be bought in reasonably small quantities for modelling. Sands really well and flexible to a point.

[ad456 210]

I checked what type of sheets I’d bought and it turns out they are HIPS so I think that’ll be why I ended up with a “blob” like @Mh1986, are your sheets HIPS or ABS?

And I’ll second Milliput and Isopon. I tend to use Isopon more often as it’s easier to spread on a bigger area and I like the smell

[Mh1986 9]

I imagine my sheets must be hips not abs, the advert simply says styrene sheet.  It has come out fairly well with just the abs slurry, however I find it quite difficult to sand smooth without damaging the surrounding areas, filler may have been easier in this respect. The slurry also leaves small air bubbles which I was hoping the primer and paint may have filled in but have not. 

[nodtec 76]

Try the glue that's used for putting plastic plumbing pipe together.  It's a bit thicker than normal modelling glue. You usually see it in blue or green but a good hardware will have clear as well.

[Willy iine 15228]

Is the GH body ABs?  I thought they were more styrene based like other hard shells?  If so I would use styrene sheets with standard plastic model cement.  Should adhere just fine.. and Tamiya putty to clean up the seam.

[Mh1986 9]

1 hour ago, Willy iine said:

Is the GH body ABs?  I thought they were more styrene based like other hard shells?  If so I would use styrene sheets with standard plastic model cement.  Should adhere just fine.. and Tamiya putty to clean up the seam.

Thanks for the advice, I'm not really sure what the shell is made of, if it's the same as the wheels it is ABS. The styrene sheet has bonded to the shell just fine. My issue seemed to be having any styrene sheet In the acetone prevented it from become a smooth lump free liquid Slurry).

[Mh1986 9]

Now I just need to modify the decals.