Filling seams

[NOBLNG]

I am sectioning a ‘51 Chevy. I got the panels tacked back in place with Tamiya solvent and bits of styrene and CA. Due to a poor cut, I have a fairly large gap in spots. I’m not fond of the idea of filling the cracks with CA or putty. For access to the interior joint, I made this little scraper from 1/16” stainless tig rod and chucked it in my pin vise. I also made one 90 degrees to this one for the vertical seams. After gouging out the seam I glued in some 1/16 Evergreen half round with copious amounts of Tamiya thin cement and smushed it into the trough. When it’s good and dry I will do the same to the exterior.

On the exterior, I can use the butt end of a drill bit. Some places I can get away with nothing or .020” round for filler and some I need .060” half round.😳

Edited February 25 by NOBLNG

[Jim Dodson]

Whenever I see topics about filling seams I flash back to my young and stupid days, you know yesterday LOL when I used too much solvent based putty in one location and by the time it had dried I had a massive warp in the piece. Be cautious with any kind of solvent based solution.

[NOBLNG]

On 2/14/2025 at 3:26 PM, Jim Dodson said:

Whenever I see topics about filling seams I flash back to my young and stupid days, you know yesterday LOL when I used too much solvent based putty in one location and by the time it had dried I had a massive warp in the piece. Be cautious with any kind of solvent based solution.

Believe me I know what you mean. 😬 On my ‘41 Plymouth I used a thick layer of Sprue Goo underneath and softened the entire top surface of the front fenders. This is much more localized.

Edited February 17 by NOBLNG

[dmthamade]

Yup!! Any time i've had a big gap to fill, i've used stretched sprue or rod stock with thin cement. Gives a much stronger weld than filler putty or CA.  Gouging or "V" ing out the joint then filling is like MIG or ARC welding, gives better penetration=stronger weld.

 

Don

[NOBLNG]

No putty on the section seam yet. It will take a skim coat in a few spots…mostly because the two panels weren’t exactly level.

[Ace-Garageguy]

Looks like a good technique to me.  

[Mark]

That sectioning job looks great, it reminds me of that 1:1 early Fifties Oldsmobile that Valley Custom built.

Regarding the sprue filler: I was big into that stuff and did use it properly (not winding up with warpage due to its shrinking while setting) but have since moved on to epoxy putty.  Pick a good one (white Milliput ain't bad) and apply it properly, and it's great.  It's the closest thing to the styrene itself when it comes to trying to scratch in panel lines, which is one part of these jobs that I don't look forward to.

[bobss396]

When I do something similar, on yhe hidden side, I use fingernail wrap material on the seams.

It has an adhesive backing, stick it on and use a thin CA glue over it. Strong like bull 💪. 

[customline]

7 hours ago, bobss396 said:

When I do something similar, on yhe hidden side, I use fingernail wrap material on the seams.

It has an adhesive backing, stick it on and use a thin CA glue over it. Strong like bull 💪. 

I just ordered a roll on Amazon.  It's 1 1/2" wide and 40" long. Lifetime supply (for me) for 4 bucks. Great tip, Bob!  Thanks! 👍......I hope I bought the right stuff. 😞

[Mattilacken]

Neat sectioning! and that tecunice seems good! What i have com to use latley is CA and bakingpowder/bikarbonat. That makes for a stong bond as well and wont usaly break of that easily.

[bobss396]

16 hours ago, customline said:

I just ordered a roll on Amazon.  It's 1 1/2" wide and 40" long. Lifetime supply (for me) for 4 bucks. Great tip, Bob!  Thanks! 👍......I hope I bought the right stuff. 😞

I bought one small box of the stuff and it lasted 20 years, I bought another box recently.. it may outlast ME. 

I find lots of cool stuff in beauty-supply shops.

[bobss396]

This is the stuff I mentioned. Sally Hansen is another brand. 

[NOBLNG]

I prefer a “welded” seam wherever possible. JMO.

[customline]

11 hours ago, bobss396 said:

This is the stuff I mentioned. Sally Hansen is another brand. 

I wasn't sure but it seemed like the right thing 👇.  Think it's ok?

Sorry, Greg 😔

Edited February 20 by customline
J

[rattle can man]

A good solvent cement should weld all of the pieces into one piece.

Since super glue and epoxy are physical bonds (they don't fuse the parts into one piece) the back of the joint with mesh will help strengthen the joint and keep it from cracking breaking. Just like real fiberglass repair is reinforced with a few layers of cloth and resin.

Either method should work.

 

[bobss396]

9 hours ago, customline said:

I wasn't sure but it seemed like the right thing 👇.  Think it's ok?

Sorry, Greg 😔

It looks like it should work. You certainly have enough to last a while. 

I used the silks recently. To attach the rear panel on an old MPC stock car.

[dmthamade]

On 2/19/2025 at 10:49 AM, NOBLNG said:

I prefer a “welded” seam wherever possible. JMO.

Me too. Being in the 1/32 aircraft world, there are times where the seam is 8-10 inches sometimes longer. Liquid cement+sprue/plastic stock=a seam literally welded together. I have tried using CA for long seams, but have had them crack when sanded. Now this wasn't with the nail wrap reinforcement, success experiences you guys give say it's something to look at. Question, is the wrap porous?

 

Don