Masking future glue spots

[NOBLNG]

I want to spray paint the engine of a model. There are a dozen little spots where the manifolds, distributor, etc. are to be attached. Does anyone have a trick for masking these areas, or do you just scrape the paint off later. I looked at some microscale liquid mask at the  LHS today, but it said not to use acrylic paints over it. Is there a better brand available?

Thanks, Greg.

Edited March 1, 2018 by NOBLNG

[Snake45]

I wouldn't bother masking the glue points. The parts you mention can be attached easily right over/through the paint with superglue, epoxy, or even for that matter, Elmer's or Tacky Glue. 

[ScottH454]

I use the microscales mask that is water release. The thing I noticed when you paint over it then it seals it. So still had to scrape it open for water to get in there. Maybe if there was a rubber type that can rub off. I use it for glue points an to avoid over painting into details.  To just glue your parts to the painted surface leaves you to the mercy of how well the paint is sticks. An I have seen it fail enough to not recommed that, especially if you still need to handle the parts.

[StevenGuthmiller]

I have almost never scraped painted surfaces for gluing in my entire 40+ years of modeling.

If you're using glues other than regular model cement or any other glues that bond by melting the plastic, I find that it's rarely necessary.

I've never had much of a problem with it.

 

Steve

[Casey]

 

[NOBLNG]

Nice tip Casey! None of these are through holes though, so I guess I am stuck with scraping. Maybe I will do a test to see how the regular testors cement sticks through paint. Or maybe I'll just brush it.

Edited March 2, 2018 by NOBLNG

[Casey]

2 hours ago, NOBLNG said:

 None of these are through holes though

Even easier to use white glue then, IMHO. You can control the size of the "drop" easily, and thin the glue a bit with water as necessary, too. Allow it to flow into the hole, and allow surface tension to have the glue "stick" to the walls/side of the hole/depression.

[John Pol]

I use Mod Pod glue for masking sometimes

[NOBLNG]

8 hours ago, Casey said:

Even easier to use white glue then, IMHO. You can control the size of the "drop" easily, and thin the glue a bit with water as necessary, too. Allow it to flow into the hole, and allow surface tension to have the glue "stick" to the walls/side of the hole/depression.

How easy does it come out ? If I have to drill it out, I may as well scrape paint.

[Casey]

2 hours ago, NOBLNG said:

How easy does it come out ? If I have to drill it out, I may as well scrape paint.

It's white glue, so easy to pick out as there is very little bond strength-- just enough to keep it in place. Stab it with a pin or needle, pry a tiny bit, and out it should come.

[peteski]

I use liquid masking material for this type of masking.  But Elmer's white glue shoudl work just as well.  I do this because I'm a "belt and suspenders" kind of modeler and I hate scraping paint from parts to assure good glue joint.

 

Here is an example of masking (after the masks were removed). The kit's plastic is yellow. I liquid-masked the cylinder heads, the engine block in the oil pan area, the top of the carburetor (to glue on the air filter), the wheel hubs on the axles, and many other areas no visible in this photos. Also on the interior tub I masked the area for the gear shifter, dash attachment and seats. The seat masking was done with pieces of masking tape (not liquid mask). The door panels were made from white plastic and their edges were also masked.

[montecarlo1980]

Just read this topic and one little trick I do for situations like this I don't want a paint build up in a sensitive area is I use good old silly putty. You can take a very small amount and push it into the holes for say the distributor etc, and the putty will fill the hole and you can paint your parts. When your paint is dried, you an use a toothpick tip to pull the silly putty right out. I have never had any issues with this method using any enamels, acrylics or lacquer paints so far in the last 30 some years doing this trick. Try it out next time it might work for you. I've been using silly putty since I was a kid for masking things off. A little goes a long way too. 

Edited March 25, 2018 by montecarlo1980

[High octane]

Sounds like a lot of extra work to me, when just a little scraping with the tip of an Exacto knife would do the job.

[StevenGuthmiller]

2 hours ago, High octane said:

Sounds like a lot of extra work to me, when just a little scraping with the tip of an Exacto knife would do the job.

That was my thought exactly!

 

Steve

[montecarlo1980]

Well if you're open minded nothings too much work  Never been for me it actually only takes but a couple seconds and never have to worry about any knife slips on delicate parts or sections. But go with what works for you. Just another idea to try. 

[peteski]

14 hours ago, High octane said:

Sounds like a lot of extra work to me, when just a little scraping with the tip of an Exacto knife would do the job.

Some people are more anal fastidious than others. There is no point explaining to you all the nuances of why masking is better than scraping.  It works for me, and I enjoy applying masking and not having to scrape.

Edited March 26, 2018 by peteski

[NOBLNG]

On ‎3‎/‎25‎/‎2018 at 3:03 AM, montecarlo1980 said:

Just read this topic and one little trick I do for situations like this I don't want a paint build up in a sensitive area is I use good old silly putty. You can take a very small amount and push it into the holes for say the distributor etc, and the putty will fill the hole and you can paint your parts. When your paint is dried, you an use a toothpick tip to pull the silly putty right out. I have never had any issues with this method using any enamels, acrylics or lacquer paints so far in the last 30 some years doing this trick. Try it out next time it might work for you. I've been using silly putty since I was a kid for masking things off. A little goes a long way too. 

I was wondering if there was any silicone in silly putty, since silicone can cause big problems for paint jobs. Turns out it IS silicone and boric acid. Have you had any paint issues when using it? I googled using it as a mask, and it turns out hobbyists of all types use it with great success. I think I will give it a try, and just be careful not to get any where I don't want it and wash my hands frequently.

[montecarlo1980]

9 hours ago, NOBLNG said:

I was wondering if there was any silicone in silly putty, since silicone can cause big problems for paint jobs. Turns out it IS silicone and boric acid. Have you had any paint issues when using it? I googled using it as a mask, and it turns out hobbyists of all types use it with great success. I think I will give it a try, and just be careful not to get any where I don't want it and wash my hands frequently.

In my 30+ years of experience using it.. I have never had a paint issue of any kind with it. I've used every brand you can think of throughout masking with it for odd parts and never had an issue. I also do lots of other things outside of model painting and have never had issues with it. I used it masking guitar bodies as well for certain curves where most tapes just won't work for getting a perfect curve. And I have yet to have any issues with it. But I'm also a take my time kind of guy I don't need to have painted thing done in 5 minutes and move on. So I can see how some would still want to use other methods. 

But I have yet to find any kind of issue of it not working well coming off out of the part for models, or affecting the paint finish. Otherwise I would stop using it if it did. So far never been an issue.