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Tips & Tricks
Ask about and post about tips and tricks you use while modelling.
Dealing with small parts, very small.
Mortifa
#464
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British Columbia, Canada
Joined: December 02, 2016
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Posted: Monday, July 17, 2017 - 08:40 AM GMT+7
The instrument panel.


Be happy to hear some ideas as to how to place the adhesive better before I attach the part, thought it look good and then... Still looks good in the cockpit.

First model where I am seriously working on PE.

The Nashorn is almost done, will post pictures of it completed, great learning experience from both of these and the tips posted here have helped, thank you.
Mortifa
#464
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Posted: Monday, July 17, 2017 - 08:29 AM GMT+7

Quoted Text


Quoted Text

What do you mean with adhesive pe?


I think he's refering to PE with that comes pre-applied adhesive on the back, like Eduard does on some of their PE sets. I've never used those yet, but they're supposed to work by simply peeling the part off the backing sheet and sticking it on.



Yes, that is exactly what I am talking about.




This is the cockpit and I still have some work todo, but the adhesive PE looks good, need to work on my placement though.



Now this is where I have another question. As you can see there is some painting done, but the one piece of PE was already pre-painted, but what do I do to attach this piece, which has no adhesive, to the painted part. From what I understand I cannot use CA as it will mess up the paint. Whiteglue? Or maybe Future? Or a Gloss coat?
Anmoga
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Posted: Saturday, July 15, 2017 - 07:00 AM GMT+7
Thanks Eetu for the clarification.
vincefromitaly
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Posted: Saturday, July 15, 2017 - 02:22 AM GMT+7
I have a few Xuron cutters and whilst I like their precise cut, I found out that still the easiest way to overcome the problem of small, brittle parts that often are connected to the sprue by means of way too large gate attachments is by using the good old razor blades.
The ones that were used back in the past where disposable little plastic razor blades were not available and you had to use them inside a metal razor that opened from the top.
I hope I have explained myself.
The advantages are:
1) you reduce to zero the stress that breaks off the small part when you try to nip it from the sprue
2) the cleaning of the residues from the part are much easier and more precise because of the thinness of the blade.
I use Gillette Silver Blue blades, I hope they are still available in your country.
Emeritus
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Uusimaa, Finland
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Posted: Saturday, July 15, 2017 - 12:14 AM GMT+7

Quoted Text

What do you mean with adhesive pe?


I think he's refering to PE with that comes pre-applied adhesive on the back, like Eduard does on some of their PE sets. I've never used those yet, but they're supposed to work by simply peeling the part off the backing sheet and sticking it on.
Anmoga
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Posted: Thursday, July 13, 2017 - 01:03 AM GMT+7
What do you mean with adhesive pe?

If you mean that it is sticky because of the tape you can use alcohol or acetone to clean it. Be careful if you use acetone since it can attack plastic. You could also try to use Tamiya masking tape instead of the tape you are using.

If you mean how to glue them it depends. If it is a flat small piece on plastic you can use gloss varnish which will give you time to put the piece on place otherwise you can use cyanoacrilate glue.

People recommend to solder the PE pieces but I think it depends on how hard you need the union between the PE pieces.
Mortifa
#464
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Posted: Tuesday, July 11, 2017 - 02:08 PM GMT+7
Well this has been great and I learned a lot.

The plastic bag works, nicely, needs a little getting used to but it works well. Taping the part before hand makes the part easier to spot, so I do not have to paint the floor black.

I just got some Photo-etch saw blades, had them on order because the Exacto saw is a little bulky, will give them a try, but I am pretty sure they will be useful.

Speaking of photo etch I found a useful tip with working with pe but I do have a question too. First the tip, tape the photoetch, detack the tape first and then apply it to keep the pe in place. This works but my question is, anyone got tips for adhesive photo etch(pe)?
Anmoga
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Posted: Thursday, July 06, 2017 - 03:57 AM GMT+7
Something very useful are photoetch saws.

When I have a very delicate piece attached from a few points I use the saw to cut it from the sprue and latter I use the sprue cutter to make the cut more near the piece. Afterwards your normal cleaning taking into account that it is a very delicate piece.

Whenever I have a doubt that I may damage a piece with the sprue cutter I use the photoetch saw firstly.

Hope it helps somebody else.

Regards,
Angel
majjanelson
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Posted: Thursday, July 06, 2017 - 02:01 AM GMT+7


You might want to consider using a heated knife blade to cut the sprues apart (at least right at the #13 & #14), which should relieve most of the stresses when you are trying to nip off the remaining bits of sprue from the parts.

Also, look closer at your instructions and the parts. It appears to me that the shackle end is a separate part from the arm, joined with a "ball" of styrene to support the parts. Otherwise, it makes no sense for the sprue to have "13" and "14" for the same part.

HTH
retiredyank
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Posted: Wednesday, July 05, 2017 - 09:38 PM GMT+7
When building Trumpeter's JGSDF NBC detection vehicle(lots of grab handles), I found that sawing them off kept them from flying away or breaking. After you remove them from the sprue, gently sand the attachment point down.
Kevlar06
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Posted: Wednesday, July 05, 2017 - 05:20 PM GMT+7
You still have the problem of releasing the delicate parts from the substantial sprue gates (in comparison to the part). The only way to do this without placing any pressure on the delicate part is to use a powered saw-- I really recommend getting some circular disk saws from Micro-Mark. Some even come with a mandrel for the drill. But you'll also need a variable speed drill, otherwise, you may melt the part. This is the only way to get the part separated form the sprue without placing pressure on it. I've been using that method for about ten years now, and have yet to break or lose a delicate part.
VR, Russ
Dragon164
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Posted: Wednesday, July 05, 2017 - 05:08 PM GMT+7
Now that I see what you are tring to do

I start by doing what Robbie sugests then use my Xuron sprue cutters to cot the part free but not too close to the part itself.

Cheers Rob.
Robbd01
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Posted: Wednesday, July 05, 2017 - 11:04 AM GMT+7
I usually cut the part with it attached to the gates off the main sprue tree down to manageable size (see edited pic). I might be stating the obvious here so go easy on me. I actually will tape the part down if possible or roll tape sticky side out and put the part on it. I use the x-acto rounded blade #10 and just rock it back and forth not really putting too much pressure. I even will stop if necessary to take a sip of my adult beverage and continue to rock back and forth. Once free the next thing I have been using to get said part to its proper location besides the highly plinkable tweesers is I saw on a youtube vid where you take a toothpick and dip it in your favorite liquid mask (stuff to mask canopies). Let it completely dry and maybe dip it a couple of more times. To reduce the stikyness a little just touch the tip with your fingers to get the correct stickiness. (I am still working to perfect this part of the task.) Not 100% but I sure have reduced the plink to oblivion odds. However, PE is still another story though my cutting still works just takes a heck of a lot more longer and you do eat up blades. BTW I like the plastic bag idea




Cheers


Scarred
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Posted: Wednesday, July 05, 2017 - 09:53 AM GMT+7

Quoted Text

Got a question.

Anyone tried using Armorall on old plastic to see if it becomes less brittle?



I wouldn't put anything like that on a model. The stuff would keep paint from sticking. In fact it would probably keep anything from sticking. One thing you can do is if you have smooth, long nose pliers, you can grab the part and protect it at the gate where it is connected and then make your cut. The other way I do it is already listed above and cut the sprue farther away from the part using a saw or my mototool than once the part is free I'll hold it with smooth long nose pliers and cut it at the gate. This will also protect the part so you can clean up mold lines and the gate with a fine file. This works great with grab handles.
RussianArmor
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Posted: Wednesday, July 05, 2017 - 06:09 AM GMT+7

Quoted Text

I use tape as a backing to hold parts in place. Like Russ Bucy said, If I can't remove it with sprue cutters safely I will use a fine saw to cut it off. I also look for tension parts and will sometimes cut the sprue section out to prevent it from being locked in place when it flexes. If there is a small bit to clean up, depending on the part and how fragile or small it is, I sometimes attach it to the kit and when the cement has dried I will then trim off any excess plastic.

For attaching the tiny parts, I use a small piece of poster tack to pick up the part. I have lost too many parts when they pinged out of tweezers. I can set the part and position it with the point of a #11 blade. Less often, I will use the blade itself, either poking the part gently or moistening the blade and picking up the part-this has worked well with etch. Just enough to grab the part and hold it for positioning. I use Tamiya extra thin, Bob Smith Industries odorless CA or lately Gorilla brand regular CA glue I get at the local home supplies store. It has a brush applicator that I can touch a part to more carefully to control how much glue I put on.



I use a wax pencil to pick up and place small plastic and PE parts. Holds well, and releases the part when you touch it to glue
Mortifa
#464
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Posted: Wednesday, July 05, 2017 - 05:18 AM GMT+7
Got a question.

Anyone tried using Armorall on old plastic to see if it becomes less brittle?
Removed by original poster on 07/05/17 - 00:31:24 (GMT).
russamotto
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Posted: Tuesday, July 04, 2017 - 02:17 PM GMT+7
I use tape as a backing to hold parts in place. Like Russ Bucy said, If I can't remove it with sprue cutters safely I will use a fine saw to cut it off. I also look for tension parts and will sometimes cut the sprue section out to prevent it from being locked in place when it flexes. If there is a small bit to clean up, depending on the part and how fragile or small it is, I sometimes attach it to the kit and when the cement has dried I will then trim off any excess plastic.

For attaching the tiny parts, I use a small piece of poster tack to pick up the part. I have lost too many parts when they pinged out of tweezers. I can set the part and position it with the point of a #11 blade. Less often, I will use the blade itself, either poking the part gently or moistening the blade and picking up the part-this has worked well with etch. Just enough to grab the part and hold it for positioning. I use Tamiya extra thin, Bob Smith Industries odorless CA or lately Gorilla brand regular CA glue I get at the local home supplies store. It has a brush applicator that I can touch a part to more carefully to control how much glue I put on.
Kevlar06
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Posted: Tuesday, July 04, 2017 - 07:54 AM GMT+7
This is where that fine toothed circular saw from Micro-Mark comes in really handy when chucked in my variable speed Dremel-- I would have removed a chunk of the sprue with the part attached, then used the circular saw right up against the part. Now you'll need to reconstruct the part with fine brass wire.
VR, Russ
justsendit
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Posted: Tuesday, July 04, 2017 - 07:04 AM GMT+7
With the type of sprue connector you show above, I generally clear the deck, think happy thoughts, and mentally prepare for a scratch-building session.

Some kits are just molded with Styrene which is either too brittle or too soft, and then there are those which can have a near perfect composition.

As far as handling parts once they are free, you might try a different set of tweezers. I've found that not only the tip shape, but also the spring tension, and how much pressure you apply can make a big difference. If the tips fail to stay aligned at the critical moment, you can almost always count on the dreaded "PLINK!" 😝

My favorite go-to tweezer is a pair from a cheap set of (6) that I purchased years ago on Amazon.

HTH.
mike
Mortifa
#464
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Posted: Tuesday, July 04, 2017 - 04:36 AM GMT+7
Here is one of the parts that just blew apart when I was trying to cut it off.



And you can see the destroy part on the other sprue.

So, is this because it was an old kit (Dragoon 6001)? Any tips for dealing with old plastic?
Kevlar06
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Posted: Thursday, June 29, 2017 - 06:44 PM GMT+7
This is how I approach the problem:

1) I use a pair of Xuron flat sprue nippers to cut the sprue close to the part, but not right at the sprue gate.
2) if the part is large enough that I can get the flat sprue nippers up against the gate where the part is, I just nip it off with the flat side against the part.
3) if I can't get the Xuron nipper in there, or if the part has two or more sprue gate attachment points (i.e; a grab handle) I use a fine tooth circular saw chucked in my variable speed Dremel tool (available from Micro-Mark) to separate the part from the sprue. A pair of cross-tip tweezers is helpful for holding the part when cutting with the circular saw.
4) if I think I might loose the part, I stick it to blue painter's tape or a small pad of Silly Putty along with a chunk of the sprue and sprue gate.
--Hope this helps
VR, Russ
Mortifa
#464
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Posted: Thursday, June 29, 2017 - 05:07 AM GMT+7
Thank you all for the responses.

Plastic bag, so brilliant, wish I had thought of that.

I used Testors before but I read so much about new glues I was trying them and my Testors, granted it is about twenty years old, is not working like it used to, comes out as goo, sort of.

Hopefully we will get more tips, as all of these have been good.

Will post pictures, the blue-tack melted into the hull is shocking, and I also ordered some of the PE saws, using an Xacto saw, about six inches, works great but still the fragile pieces just blow up. I agree they should supply extra of the very fragile pieces.

165thspc
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Posted: Thursday, June 29, 2017 - 01:50 AM GMT+7
As far as handling small parts in general: "ya pays your money and ya takes your chances."

If using clippers or a knife; shield the part to deflect it from flying off into never never land. Never thought of cutting it off while inside a a large clear plastic freezer bag but that is an idea worth trying.

Recently some have been selling PE etched saw blades to saw the small part off the sprue. Sounds like a good idea that I need to try.

Also try to analyze the stresses placed on a part when cutting with the nippers. Sometimes a few advance cuts made in other areas of the sprue can reduce or eliminate the stress of the final cut.

As to freeing small handles and hand grabs I just wish the model manufactures would give you extra, knowing full well that some will break.

One man's opinion. Worth every penny you paid for it!
165thspc
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Posted: Thursday, June 29, 2017 - 01:41 AM GMT+7
I agree with Matt above. Free the part, get a hold on it, apply glue, wait a few seconds and apply part to model.