Discussion in 'Tutorials and how to's' started by Samh93, Apr 9, 2011.
I always mask with Tamiya tape (or similar) and Blu-Tac if called for.
Did you apply the filler over gloss white paint I wonder (being concorde) If so this may be the problem. Filler probably won't stick too well to a gloss surface. Is so, sand back the paint to bare plastic, and try again.
I use plain old Humbrol filler, It dries very quickly, which might be a problem for some, but at least your not hanging around for ages !
I'm with Steve on Tamiya tape - it's really good stuff. But I tend to use normal masking tape for holding bits together, saving the Tamiya for the important jobs.
Thankyou for the info guys
I've never really got on with liquid mask either though some people swear by it. It tends to make a mess and end up in places where I don't want it LOL.
For sand paper I use wet'n'dry from Halfords,mostly grades between 800 and 1500 grit.
If a kit has small windows; port holes on a boat, windows in the side of an aircraft fuselage, I have been known to leave them out and after the model is painted use Microscales micro klear to fill the hole. As it dries it turns clear but a perfect window glass it is not. The effect is good though and you do end up with a very thin window.
Larger windows I mask before I put them in, like Stona.
Filler; I use both squadrons white and Green, also Humbrols. They do dry quick though. You can thin them down with liquid glue and paint it on with a brush. This is very good for pin marks and other scratch marks as you can put it right where you need it.
Big holes/gaps get filled with Milliput.
Not the common super glue found in shops.
There is a great selection. Thin, medium & thick. A gel. A brush on. And another manufacturer has a powder you place in the gap & then put super glue on top of the powder. The thin one wicks into small gaps & is good for re-glueing a poor joint.
Some are faster to go off some retarded. There is also an accelerator to apply after you have everything else completed.
Price to pay if you are not careful. Fingers suddenly become part of the wing or you suddenly lose a finger to your thumb. Joking apart they are lethal if not used with extreme care. Use specs or goggles, store away from children.
With care they are great extremely strong & give good results. When they have gone off get down to filing & papering immediately as they get stronger in time, Fast.
A new outlet is Filla-Glu Product Range
Also I have bought from another outlet but the one above seems to have a number of good innovations & it seems to be better presented for applying.
For applying wings it is really strong compared to the poly cements stuff. But you have to be able to set up quickly & be neat & tidy. Like all modelers ???
That first point is vital as the glue/filler quickly goes off harder than the surrounding plastic with inevitable difficulties at the sanding stage. You can soften it with acetone or an acetone based nail varnish remover.
I would beg to differ about the relative strengths of the bonds,but a good bond can only be achieved with poly cements if you have two surfaces that match up. It is useless in a gap. A well made joint using poly cement will fill itself with "molten" plastic and not need filling. It will also be very difficult to break apart,CA joints can usually be seperated relatively easily if you apply a shearing force.
I tried it on a a discarded model. Poly glue snapped at the joint. The super glue joint not only held but the wing snapped off further down. It does not shrink as it does not have a solvent, as poly glue, therefore has a 100% contact with the material. Look very closely at poly glue joint & you will find that there are minute air bubbles.
Super glue providing you use the correct product is used as a gap glue in many industries.
The point I was making is that you get at the joint as soon as the glue is hard enough to work. That is in secs of it going off. If you do that I have joints which are far superior to all the other fillers I have used. You must however make sure that you only fill as flush as possible to avoid extra work.
Another use which I forgot to mention. Small fragile items such as aircraft masts, machine guns glued to wings, pitot tubes are easily damaged & broken off. If you with a brush type super glue apply a very thin coat to these items the item is greatly strengthened.
Lazy calling them superglues as they are Cyanoacrylates.
I think at something like a wing/fuselage join a CA glue may well be stronger. These types of joins never have a continuous length of two surfaces in good contact over enough area.
It's the reason we have to fill them in the first place. I use CA myself in this circumstance,as I said,Poly cement is useless in a gap.
I still believe that along a well prepared seam where you have to mating surfaces a properly applied Poly cement will "weld" the two sides together. I do short lengths at a time and squeeze un til some dissolved plastic oozes from the seam. After allowing time for the join to dry and "outgas" I get a seam which will need scraping but not (9/10) filling. If filling is needed it is usually because I hadn't prepared the mating surfaces as well as I thought I had. I bet we've all been there! I tried seperating such a seam on an old model recently,looking to recycle some internal parts,and ended up breaking the model up. I've just tried seperating to halves of a scrap wing with a more equivocal result,the seam did seperate along about half the leading edge but it took some doing.
I agree absolutely with CA's gap filling ability,again,I use it myself. I just wanted less experienced modellers to be aware that you do need to get at it quickly or it can be difficult to deal with.
Good tip for strengthening "dangly bits" too. If I had a quid for every pitot tube I'd snapped off........
My apologies I had misunderstood your comments regarding the filler properties & got poly mixed with superglue.
Must say that after all the above though I have found good use for it I hate the process of using it.
If I had another quid for every time I'd stuck a piece of plastic ,photo-etch,my body,a family pet or clothing to something else with the damned stuff I'd also be a rich man! I too find the process of using it irksome but unavoidable.
On a slightly different tack,do you find that CA glues go off? I'm sure that some,it seems to me particularly the thinner "concoctions", go off fairly rapidly once opened. I have a somewhat distant background in chemistry and have suggested to the missus that I should be allowed to keep it in the fridge but this suggestion was met with a response more frosty than the ice box!
Visions of a leak & your wife walking around with a frozen chicken super glued to her finger.
New, Unopened containers of any instant glue may be stored in the freezer (at or below
32 F) to double shelf life. Always allow the container to warm to room temperature before opening. Once opened, never return an opened bottle to cold storage. Why ? -- Moisture is one of the catalysts. Opening a cold bottle or placing a previously opened bottle back in cold storage causes the warm air that has entered the bottle, (carrying moisture with it), to condense the moisture into water. This has a negative effect on shelf life causing the contents of the bottle to thicken and eventually harden and causes the spout to clog very frequently. The thicker these glues become, from the original viscosity, the more frequently clogs occur.
Note: This is not to say that the gap filling versions are more likely to clog.
I read somewhere that shelf life was about 5 years but dependant on conditions.
AGE or Foreign Matter:
Shelf life is determined, to a great extent, by the quantity in the container. As a rule of thumb, a two ounce bottle has a one year shelf life at room temperature. As the bottle ages and passes the expected useful lifetime, it begins to thicken. This can also occur because of improper storage or because of foreign matter being introduced into the bottle, as explained above. If you are very familiar with these glues, you know that even glue thickened because of any of the reasons above, is still usable as if it were gap filling versions. NEVER add new glue to an open bottle as the older glue will shorten the shelf life of the new.Large bottles of glue are poor economy unless a smaller container is used up entirely within 4 weeks.
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