discussion Sanding-down

[Guest]

Good afternoon,

Can anyone offer some advice on sanding-down seams after they've been filled.

I fill small seams with superglue and then sand-down with 400 grit, 2000 grit and then 5000 grit; but it seems to take ages.

Regards

Andy

 

[Paul Davies]

Have you tried model filler. I use humbrol this still takes a while to sand down but I bit easier than sanding superglue

 

[Guest]

Andy the best advice I can give is to first use Mr Surfacer 500. This is assuming the seam gap is not excessive if so then use slices of plastic card (all different sizes available) fitted into the joint and using Tamiya Extra Thin or Mr Cement S. These two will melt the plastic into each other or weld together.

Then on the thin seam joint or the card filled one use the Mr Surfacer 500. This I apply in layers until the joint is filled. You can use IPA to smooth the 500 down or as I do use 1200 0r 1500 wet and dry paper with a good application of water. Apply if you have not completely more layers of 500 until the joint is perfect.

You may have to re-scribe panels after. But 500 is about the same hardness as the plastic and you can with care scribe well. You will also get nice transitions between the plastic and 500 edges as the 500 will sand down to nothing without crumbling at the edges. Do not think there is an easier way which provides such a good smooth joint. Done well yo will not see the filling or joint through the finished paintwork. But it does entail that awful thing patience.

I would not use 500 on a painted surface/primed surface as it will ruin paintwork and not adhere to the paint surface satisfactorily.

Just add that superglue is not good as it is harder than the plastic and will not make a good joint.

Laurie

 

[Guest]

i use Deluxe Materials perfect plastic putty dry's in minutes and sands really easy and is ideal for small gaps

 

[stona]

I like to use super glue as a filler too. The trick is to sand soon after applying the glue, before it has had time to cure. Leave it a short time to dry (a minute or two, but it depends on the glue) but not cure. Superglue will almost invariably cure to be harder than the surrounding plastic making sanding smooth very difficult.

Most plastic putties shrink as they dry which I find irritating, they often need more than one application and they have virtually no adhesive qualities. This is why I use super glue for small gaps and an epoxy like Milliput for larger ones.

I do use Mr Surfacer (mentioned above) to sort minor imperfections. It is good stuff.

Cheers

Steve

 

[Guest]

I've just started using mister surface 500 and 1000 but some patience is also a requirement as well.

scott

 

[Guest]

Most plastic putties shrink as they dry which I find irritating, they often need more than one application and they have virtually no adhesive qualities

Agree entirely. Also to add that the surface finish on these is grainy. If I resort to these at times due to an area not being suitable for other types I sand fractionally below the surface and then coat with Mr Surfacer 1000.

Laurie

 

[Guest]

http://www.ebay.co.uk/itm/321643541626?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

this is the stuff i use and it says it doesn't shrink or crack so far so good for me i would recommend it for small gaps

 

[Guest]

Thanks for your advice. What grit sandpapers do you use?

 

[stona]

I never use anything harsher than 800 grit and work my way up to 1200, 1500 and 2000. After that its polishing really.

For things that need more radical adjustment I tend to use files.

Cheers

Steve

 

[aaron]

Mr dissolved putty for me, I put it on then using a Cotten bud damp with laquor thinner to wipe smooth. No sanding for me.

 

[Guest]

anything from 80 grit - 800 grit wet and dry works for me if i need any more i just carry on till all the sanding marks are gone

 

[BarryW]

For filler, I use three:

Mr Surfacer 500

Mr Dissolved Putty and

Vallejo Plastic Putty

Each has its particular use. Mr Dissolved is particularly good when rubbing down stubborn joins or for very small gaps in difficult places where you need self-levelling qualities. I have also used it when I need to 'smooth' a rough surface. Mr Surfacer I use for joins that need somethign a bit thicker. Vallejo is good for gaps. All three can have the surplus removed with a cotton bud and ipa.

 

[Guest]

Anybody tried Micro Balloons mixed into superglue / epoxy / what have you? it was a trick used in my old RC modelling days to keep things light, but one really useful side-effect was that even epoxy and Cyano would sand really easily!

 

[Ian M]

Hmm Micro ballons.... Talcum powder has been used to good effect.

If I am building a resin kit I carefully collect the sanding dust in a small container. For super-gluing things that need a real good solid join that will not be seen, I give it large with the super glue, then a good sprinkle of the resin dust so its about 50/50. Sands off ok.

Like Barry, I often use Vallejo putty for small cracks, and wipe it smooth with either IPA or if still wet, good old water on a cotton bud.

Milliput two part putty is great stuff. Great for nasty joins, can be smoothed off with water while wet.. You can also use it to make rather good complex shapes, like flags and tarpaulins.

Just roll it out on talcum and way you go.

Oh good old Humbrol filler is not that bad. It can be thinned down with cellulose thinners and painted into small cracks., almost forgot that one.

Ian M

 

[Guest]

There is a good lot here. I have learnt a few tricks. Although there have been other articles on the same subject new ideas and forgotten ones and variations on the usual just keep on rolling out.

It just shows that even looking at old articles in the archives it is worth reviving some subjects.

Laurie

 

[Gern]

One that's not been mentioned is ordinary PVA - but only in joints where the two pieces are vertical to each other. You can paint it on with a small brush and use a larger, slightly damp brush to clean the excess before it dries. Because it is fairly thin, capillary action draws it into the joint, but it is thick enough to form a skin against both sides of the join and surface tension pulls it into a nice curve against them.

 

[Guest]

For filler, I use three:
Mr Surfacer 500


Mr Dissolved Putty and


Vallejo Plastic Putty


Each has its particular use. Mr Dissolved is particularly good when rubbing down stubborn joins or for very small gaps in difficult places where you need self-levelling qualities. I have also used it when I need to 'smooth' a rough surface. Mr Surfacer I use for joins that need somethign a bit thicker. Vallejo is good for gaps. All three can have the surplus removed with a cotton bud and ipa.

Following advice on this forum I am using Mr Surfacer 500 & 1000 and find them ideal. Can someone please tell me what IPA is please? I am rubbing down with wet & dry.

 

[Gern]

IPA is Isopropyl Alcohol. There are lots of sites on ebay which sell it and it's not expensive.

 

[Guest]

IPA is Isopropyl Alcohol. There are lots of sites on ebay which sell it and it's not expensive.

Okay, thanks for that