Glue painted parts togehter ?

You have to scrape off the paint so that the glue can make a positive bond on the mating areas. I either use a thin strip of masking tape to cover the attaching point on the leg and a small dab of blue tak on the mounting hole in the well to keep the paint off.  

Ordinarily I also use a hobby knife to scrape away paint from join surfaces.  However, if the join area is very small, and difficult to scrape, I use a small drill in a pin vise to drill one or two shallow pits in each surface, making sure it completely penetrates through the paint.  This may be easier than scraping, especially on a fragile part, but if you use CA the bond will still be pretty strong.

I too, typically, scrape off the paint on the surfaces that I intend to join; however, I have also used CA and an accelerator to bond areas after painting, specifically, I did this on the landing gear on a 1/32 Bf-109. So far, this has produced a super-strong join.

Nice tip on the tape PJ.

Problem with superglue is the bond is only as good as the paint to plastic bond. often the only way to go, however.

Yeah, scraping paint away is always your best bet.  You've got to make sure that the glue makes contact with the plastic and you have a plastic to plastic connection.  The glue isn't really a glue... it actually melts the plastic slightly and allows it to fuse with the plastic it comes into contact with.  So if you think of the "glue" as more of a "solvent" it starts to make sense.  However, there's nothing wrong with using superglue or epoxy either.  Just remember thou, when using Superglue the fumes will haze clear parts so as long as you don't use it anywhere near a clear part you should be fine... as for epoxy, it can be rather difficult to work with.  Especially if you're using only a small amount.  Its hard to mix a small portion and most epoxies have a rather quick curing time so you have to work fast before it hardens.  And when you're talking small parts, fast is a word you wanna steer clear of.  I don't know how many tiny parts I've lost to the carpet monster over the years because I was rushing to get a part done only to find myself on my hands and knees crawling under my workbench with a flashlight trying to find the little part that supported the entire weight of the model!  Hours later you find it stuck on your pant leg and smack yourself in the head!  Oh the humility! :)  Hope this helps!

Sometimes you have to glue painted parts together but it is much better to scrape if you can.

JMorgan

Sometimes you have to glue painted parts together but it is much better to scrape if you can.

 

Many have given excellent advice here ;

   Now for an old dog like me , I still do what I was taught over 60 years ago .That is Scrape or don't paint a glue surface .

 Every kit I've built over the years , says right in the instructions ," scrape paint from areas to be glued ". This is good sound advice that cannot be repeated enough .

      Also a good note from " G " , Superglue is fine , But the joint is only as strong as the paint adhesion to the surface of the model or part .    T.B.

plasticjunkie

You have to scrape off the paint so that the glue can make a positive bond on the mating areas. I either use a thin strip of masking tape to cover the attaching point on the leg and a small dab of blue tak on the mounting hole in the well to keep the paint off.  

 

PJ, make oyur mask job even easier by using a little blob of blue tac on the LG end as well. Easier than trying to tape a tiny little thing.  

wing_nut

 

 

 

 

PJ, make oyur mask job even easier by using a little blob of blue tac on the LG end as well. Easier than trying to tape a tiny little thing.  

 

Thanks, that's a good tip, one I never thought of...

Elmer's is pretty good for that too. I find it's a great way to mask little dots. Just apply a drop with a toothpick.

GMorrison

Elmer's is pretty good for that too. I find it's a great way to mask little dots. Just apply a drop with a toothpick. 

Great advice and it just reminded be... If you apply Elmer's glue to all your glue surfaces (edges that will be glued to other parts later) and allow it to dry before you start painting, you can just peel the dried glue off and the surface will be paint free! EASY PIZY!  Can even thin it down with a little water (note I say a LITTLE water) and paint it on the glue surfaces to get it more precise.  I know alot of those liquid masking products that are available are basically just thinned down Elmer's glue with a touch of food coloring.  Can also be used to mask already painted areas to protect from overspray and will get into all the little nooks and crannys.  It just peels off when done so you don't have to worry about it damaging your model at all!

I like the pin vise to drill small hole.. then aplly little glue .

This seems to work great for me so far

Thank for the advice

Rick

Has anyone tried that new UV glue that they've been advertising on TV lately?  The one that you shine the UV light on and it hardens in seconds?  Thought about getting some but not sure if I should!

Yes i have tried it and like it very much. Especially on clear parts...no fogging or crazing and it sticks better than anything else i have tried.  it also makes windows well and instantly dries . I have not used it anywhere else except for canopies etc.

I've had great results using Tamiya Extra Thin on un-painted parts, and super glue (CA) on painted parts. I use a tooth pick to apply the CA. 

I've used Bondic with good results in several situations.  Keep in mind that the glue must actually be exposed to the light to cure.  You can't put it "under" the part where it is in complete shadow or it is just like keeping it in the tube.  

I scrape the paint away from the mating surfaces.  I prefer to use styrene cement to join styrene to styrene, though.  I want the weld bond that it provides

I have a little screwdriver from a cheap set.  It is a convention blade about 1/16 inch wide.  The conventional blades in the set are useless with screws because of a weakness that lets the blades twist.  But it scrapes paint nicely so I saved it as a paint scraper.  It fits into small areas where a knife blade cannot.

Six year old thread revived.

Its from a new Stephen King book, "Thread Sematary". 

"Remember, Lewis.  Sometimes dead is better."