This has probably been covered before but I was wondering if someone could share their method of removing the seam from a two pc. barrel? I almost always buy an aluminum replacement but wanted to give the kit barrel a try. Thanks in advance.

I have heard that Mr. Surfacer works well. I just glue the barrel together and run a bead of putty down the seam. Let it dry and sand to shape. I prefer generic Bondo, but have had some luck with Squadron White Putty. Another method I have used with some success is to liberally apply Tamiya cement along the seam. Let it dry for a minute and press the two halves together more tightly. Some glue should seep out along the seam. Simply remove it with the tip of a sharp razor knife, after it has cured. Hope this helps.

I've found that it's really helpful to trim away the locator pins and use a sanding block to get the mating surface on each half perfectly smooth first.

I then do as Matt suggested, apply liquid cement to both sides and align carefully squeezing some of the melted plastic out of the seam.

I allow this to dry for a couple of days so that there's little chance of shrinkage along the seam later. Trim and sand the squeeze-out. Note that the the way the molds were cut probably means that the barrel is slightly oval in cross-section, so you should have some extra material along the seams that needs to be removed to create a round cross-section.

If the joint / seam was nice and tight (the reason for sanding flat with the sanding block), you should have a nearly invisible seam. Prime it and take corrective action (sand and prime or fill again) as needed if it's not perfect under the primer.

HTH,

Careful dry fitting and making sure the mating surfaces are flat goes a long way in preventing ridges and seams. Remove the alignment stubs if the halves aren't lining up properly. Glue in short lengths and check alignment frequently. Don't clamp unless you have to and if you do, use something with a round indent (clothespins are a good choice) and make sure the barrel halves aren't being squeezed out of alignment. Let the glue set for a while and remove the clamps as soon as possible to prevent any overnight slippage. Let the glue set completely before doing any sanding or filling. You'd be surprised how easily a join can slip when you're not paying attention.

I use a flexible sanding pad or just sand paper on its own when needed. Using rigid sanding sticks or files tend to flatten the barrel. Concave (inny not outy curve) knife blades also come in handy. Tiny seams are best filled with paint, let dry and sand with extremely fine (polishing grade) sand paper, that way only the paint is being removed. Repeat if needed.

Kimmo

I knew someone else would be replying as I typed

If possible I chuck the barrel in a drill after it's dry, and using fine sandpaper to grab the barrel, run it like a lathe. After it's smooth, I'll prime it to make sure there's no trace of the seam. If there is I fill those areas with a thick coat of primer, let it thoroughly dry for a day or two, and run it again. Be warned though, use LITE finger pressure! It's fairly easy to change the barrel's profile if you don't pay attention.

All of the above work pretty well - and better for larger-diam barrels.

You can fix up the sanded plastic barrel and get a nice base finish for painting on (remember, gun barrels are machined items in the real world and their finish was generally very smooth, unlike rolled steel plates and castings)... take your barrel and dip it or brush it heavily with Future and stand it up to dry so that any excess runs down off the "hidden end". Do a couple of dips and dryings and this will give a realistically smooth and almost glossy barrel ready for prime and paint.

Bob

Same way that aircraft modellers use: apply a bead of thick liquid glue (tube glue, for instance) along the mating surfaces of each half. Let the glue stand for a couple of minutes, then carefully press the two halves together to keep proper alignment. Don't clamp unless the barrel halves are very warped. And even then, only enough pressure to keep the halves in contact. A bead of glue should squish out from the joint. DON'T remove it yet; let it dry solidly overnight. Next day trim and sand - you'll find the two halves have solidly welded together without any gaps.

All of the above and I find the use of a Flexi-File to be very useful in not only sanding the rounded contours, but also allowing me to adjust the contact sruface to avoid flattening or ovalling the barrel.


If you squeeze the two arms of the file gentley towards each other, the tension on the sandpaper stip lessens and the contact area increases, making for more gentle material removal over a larger area. By varying that tension you can really control the results on a convex surface like a barrel of a fuselage.

Paul

I brush the seam with Mr Surfacer 500,and carefully sand with a curved sanding stick so as not to flatten one side or the other

thin super glue. its so thin that it basicall runs like water. fills gaps very well, and leaves almost no trace once it dries