Airframes
Benevolens Magister
Trial and use of the Paint Remover.
It's rarely that I need to completely strip a model of existing paint, but as I wanted to refurbish a 1/48th scale Mosquito, built and brush-painted, with enamels and a tough, polyurethane finish varnish, over 30 years ago, I decided it would be a lot less effort, and probably quicker, to use a paint stripper specifically designed to remove paint from plastic models. This was also important, as the model had been converted into a B.XVI, using the old Airfix FB.VI kit and a spare Monogram "bomber" nose, with the extended engine nacelles and the bulged bomb bay formed using "Milliput", and these latter areas could easily be damaged if using a "scrape and sand" method, or, as has been used in the past, brake fluid.
The model was also extremely dirty, and the varnish had yellowed considerably over the years, with a patina of grime on top, which would need a lot of work to remove, ready for re-painting.
Having looked around, I noticed that Model Hobbies, in the UK, had what appeared to be a suitable product, in the form of "Expo" Modeller's Paint Remover, which is specifically designed to remove enamel and acrylic paints from most plastics, metal, stone, brick, marble and wood. It is shown as being water based, without fumes, does not give skin burns, and that it is free of VOC's ( Volatile Organic Compounds).
The product is a gel-like substance, in a 50ml bottle, and cost £4.71 at Model Hobbies. (Pic 1.)
Instructions.
The instructions printed on the label on the bottle suggest that the gel should be applied liberally, and removed after one hour, using a scraper or stainless steel scouring ball, and that the use of wire wool should be avoided, to prevent surface damage. The instructions also state that some plastics may be affected, and to test a small area first.
There are no safety precautions shown, and I found that what little odour there was did not have any detrimental effect on respiration or eyes, and was, in fact, quite pleasant., and I did not feel even a slight tingle when I did actually get some of the gel on my skin, unlike some other types of paint stripper !
Trial Area.
Heeding the instructions, a small area on the upper surface of the wing had a little of the gel applied, rather thinly. After around ten minutes, it could be seen that the very tough polyurethane finishing varnish was beginning to "liquefy", and starting to "lift", with the gel now acting on the enamel paint beneath. After a further ten minutes, this area was lightly scraped, and most of the paint lifted of in a "skin", although somewhat patchy, due no doubt to the light application.
In use.
Satisfied that it appeared that no damage would be done to the plastic, a fairly liberal coating was then applied to the rear fuselage, using an old paint brush, and spread around evenly. ( Pic 2 .)
After around 15 to 20 minutes, this was scraped off, using an old, blunt blade in a scalpel. ( Pic 3.)
The tail area was similarly treated, but this time, the gel was left in place for around 30 minutes, with much more dramatic results. ( Pic 4.)
After stripping the rear fuselage, although most of the paint had been removed, there was still some residue, and the decals were not removed completely, suggesting that perhaps more time was required for the gel to work properly, or that a further application was needed. ( Pic 5.)
This was duly carried out, and the remaining paint, and the decal, removed, after leaving this lighter application in place for around 10 minutes. ( Pic 6.)
Having decided that the gel worked best if left longer, I then aimed to follow the instructions, and leave it on the surface for 1 hour. However, after around 40 minutes, it was clear that the paint was now lifting easily, and these areas were therefore stripped, again using the blunt blade as a scraper, and came off easily, in large areas, leaving the plastic beneath clean and almost new-looking. ( Pic 7.)
After stripping these areas, the engine nacelles were tackled, with the gel having been in place for an hour, perhaps a touch longer. Due to the compound curves, and sometimes awkward access, stripping here was a touch more difficult, but it was noticed that the dissolved paint was now very "sticky", and formed into lumps when scraped. which collected and adhered to the surface.
At first, I thought that the plastic had started to melt on the surface, due to the length of time the gel had been in place. But it was soon evident that this was not the case - the gel, and the paint, had started to "dry out", causing the partly dissolved paint to separate, and then roll into balls, like a heavy coat of dust, once disturbed. ( Pic 8.)
Rather than apply a further coat of the gel, which might have had a detrimental effect on the "Milliput" in these areas, the model was put aside, and allowed to "dry out", when the gel, and the partly-dissolved paint then hardened. The hardened paint was then fairly easily scraped off and brushed down with a stiff brush (an old toothbrush), leaving the surface relatively clean and smooth.
Once fully dry, the model was then cleaned, using "T-Cut" (car body colour restorer) on a soft cloth, which removed most of the thin paint residue, and polished the exposed plastic.
This was followed by some light sanding of those areas on the nacelles (and part of the underside of one wing) where the paint had "balled", which successfully removed the dusty, gritty appearance, leaving a smooth surface.
The final step was to wash-down the model, using a soft cloth dampened with enamel thinners. This left the model clean, with those small patches of thin paint remaining being thin enough to not be a problem when it comes to re-painting, as they should be fine under a coat of primer. ( Pics 9 and 10.)
Summary.
This paint remover worked as advertised, and was relatively easy to use, and not too messy.
From experience to date, and, of course, depending on the type of paint to be removed ( enamel, acrylic etc), and how "heavy" the paint coats are, I would suggest that around 30 to 40 minutes is the optimum time to leave the gel in place, before removing the dissolved paint. For "stubborn" areas, the gel can be "agitated", by painting the area with the brush once the gel has started to act.
If required, and also stated in the instructions, the process can be repeated, on a partly cleaned area, in order to remove any remaining paint, or paint residue, when it was found that a slightly lighter application, for around 15 to 20 minutes, was sufficient to achieve this.
I would also suggest doing a trial on a small area first, timing the exposure to the gel, to "get a feel" for how it will behave on the particular painted surface being treated, and to apply the gel, and remove the paint, in manageable stages, rather than try to coat the entire model and remove the paint in one go.
All in all, I found this to be an effective, efficient product, easy to use, and with minimum "clean-up" required, and would recommend it.
It's rarely that I need to completely strip a model of existing paint, but as I wanted to refurbish a 1/48th scale Mosquito, built and brush-painted, with enamels and a tough, polyurethane finish varnish, over 30 years ago, I decided it would be a lot less effort, and probably quicker, to use a paint stripper specifically designed to remove paint from plastic models. This was also important, as the model had been converted into a B.XVI, using the old Airfix FB.VI kit and a spare Monogram "bomber" nose, with the extended engine nacelles and the bulged bomb bay formed using "Milliput", and these latter areas could easily be damaged if using a "scrape and sand" method, or, as has been used in the past, brake fluid.
The model was also extremely dirty, and the varnish had yellowed considerably over the years, with a patina of grime on top, which would need a lot of work to remove, ready for re-painting.
Having looked around, I noticed that Model Hobbies, in the UK, had what appeared to be a suitable product, in the form of "Expo" Modeller's Paint Remover, which is specifically designed to remove enamel and acrylic paints from most plastics, metal, stone, brick, marble and wood. It is shown as being water based, without fumes, does not give skin burns, and that it is free of VOC's ( Volatile Organic Compounds).
The product is a gel-like substance, in a 50ml bottle, and cost £4.71 at Model Hobbies. (Pic 1.)
Instructions.
The instructions printed on the label on the bottle suggest that the gel should be applied liberally, and removed after one hour, using a scraper or stainless steel scouring ball, and that the use of wire wool should be avoided, to prevent surface damage. The instructions also state that some plastics may be affected, and to test a small area first.
There are no safety precautions shown, and I found that what little odour there was did not have any detrimental effect on respiration or eyes, and was, in fact, quite pleasant., and I did not feel even a slight tingle when I did actually get some of the gel on my skin, unlike some other types of paint stripper !
Trial Area.
Heeding the instructions, a small area on the upper surface of the wing had a little of the gel applied, rather thinly. After around ten minutes, it could be seen that the very tough polyurethane finishing varnish was beginning to "liquefy", and starting to "lift", with the gel now acting on the enamel paint beneath. After a further ten minutes, this area was lightly scraped, and most of the paint lifted of in a "skin", although somewhat patchy, due no doubt to the light application.
In use.
Satisfied that it appeared that no damage would be done to the plastic, a fairly liberal coating was then applied to the rear fuselage, using an old paint brush, and spread around evenly. ( Pic 2 .)
After around 15 to 20 minutes, this was scraped off, using an old, blunt blade in a scalpel. ( Pic 3.)
The tail area was similarly treated, but this time, the gel was left in place for around 30 minutes, with much more dramatic results. ( Pic 4.)
After stripping the rear fuselage, although most of the paint had been removed, there was still some residue, and the decals were not removed completely, suggesting that perhaps more time was required for the gel to work properly, or that a further application was needed. ( Pic 5.)
This was duly carried out, and the remaining paint, and the decal, removed, after leaving this lighter application in place for around 10 minutes. ( Pic 6.)
Having decided that the gel worked best if left longer, I then aimed to follow the instructions, and leave it on the surface for 1 hour. However, after around 40 minutes, it was clear that the paint was now lifting easily, and these areas were therefore stripped, again using the blunt blade as a scraper, and came off easily, in large areas, leaving the plastic beneath clean and almost new-looking. ( Pic 7.)
After stripping these areas, the engine nacelles were tackled, with the gel having been in place for an hour, perhaps a touch longer. Due to the compound curves, and sometimes awkward access, stripping here was a touch more difficult, but it was noticed that the dissolved paint was now very "sticky", and formed into lumps when scraped. which collected and adhered to the surface.
At first, I thought that the plastic had started to melt on the surface, due to the length of time the gel had been in place. But it was soon evident that this was not the case - the gel, and the paint, had started to "dry out", causing the partly dissolved paint to separate, and then roll into balls, like a heavy coat of dust, once disturbed. ( Pic 8.)
Rather than apply a further coat of the gel, which might have had a detrimental effect on the "Milliput" in these areas, the model was put aside, and allowed to "dry out", when the gel, and the partly-dissolved paint then hardened. The hardened paint was then fairly easily scraped off and brushed down with a stiff brush (an old toothbrush), leaving the surface relatively clean and smooth.
Once fully dry, the model was then cleaned, using "T-Cut" (car body colour restorer) on a soft cloth, which removed most of the thin paint residue, and polished the exposed plastic.
This was followed by some light sanding of those areas on the nacelles (and part of the underside of one wing) where the paint had "balled", which successfully removed the dusty, gritty appearance, leaving a smooth surface.
The final step was to wash-down the model, using a soft cloth dampened with enamel thinners. This left the model clean, with those small patches of thin paint remaining being thin enough to not be a problem when it comes to re-painting, as they should be fine under a coat of primer. ( Pics 9 and 10.)
Summary.
This paint remover worked as advertised, and was relatively easy to use, and not too messy.
From experience to date, and, of course, depending on the type of paint to be removed ( enamel, acrylic etc), and how "heavy" the paint coats are, I would suggest that around 30 to 40 minutes is the optimum time to leave the gel in place, before removing the dissolved paint. For "stubborn" areas, the gel can be "agitated", by painting the area with the brush once the gel has started to act.
If required, and also stated in the instructions, the process can be repeated, on a partly cleaned area, in order to remove any remaining paint, or paint residue, when it was found that a slightly lighter application, for around 15 to 20 minutes, was sufficient to achieve this.
I would also suggest doing a trial on a small area first, timing the exposure to the gel, to "get a feel" for how it will behave on the particular painted surface being treated, and to apply the gel, and remove the paint, in manageable stages, rather than try to coat the entire model and remove the paint in one go.
All in all, I found this to be an effective, efficient product, easy to use, and with minimum "clean-up" required, and would recommend it.
