putty to smooth a joint between two sections of a plastic model


Claus Schlund \(HGM\)
 

Hi List Members,
 
It has been a few years since I did a project that needed any putty to smooth a joint between two sections of a plastic model.
 
When I pulled out my favorite tube of putty (labeled "TAMIYA PUTTY BASIC TYPE") I found it had hardened up like a rock inside the tube!
 
Oh well, I thought. I don't like Squadron putty nearly as much, but I do have a tube already and so guess I will have to use it. I opened my tube labeled SQUADRON FAST DRYING WHITE PUTTY and it is also hardened, altho not as badly as the Tamiya putty.
 
Clearly I'm gonna have to buy a new tube of some kind of putty, so I'm looking for ideas regarding what other people use. Do you have a favorite? Pluses and minuses of each? Any help regarding gotchas and/or techniques? How about using automotive spot putty from a big box store - something like Bondo glazing and spot putty - does anyone use that?
 
Opinions...
 
Thanks in advance for your thoughts on the topic
 
Claus Schlund
 


O Fenton Wells
 

I use a Bondo auto putty from WalMart.  I know all the purists will poo poo this but it works for me and it lasts a long time.
Just say'in
Fenton

On Mon, May 17, 2021 at 11:14 AM Claus Schlund &#92;(HGM&#92;) <claus@...> wrote:
Hi List Members,
 
It has been a few years since I did a project that needed any putty to smooth a joint between two sections of a plastic model.
 
When I pulled out my favorite tube of putty (labeled "TAMIYA PUTTY BASIC TYPE") I found it had hardened up like a rock inside the tube!
 
Oh well, I thought. I don't like Squadron putty nearly as much, but I do have a tube already and so guess I will have to use it. I opened my tube labeled SQUADRON FAST DRYING WHITE PUTTY and it is also hardened, altho not as badly as the Tamiya putty.
 
Clearly I'm gonna have to buy a new tube of some kind of putty, so I'm looking for ideas regarding what other people use. Do you have a favorite? Pluses and minuses of each? Any help regarding gotchas and/or techniques? How about using automotive spot putty from a big box store - something like Bondo glazing and spot putty - does anyone use that?
 
Opinions...
 
Thanks in advance for your thoughts on the topic
 
Claus Schlund
 



--
Fenton Wells
250 Frye Rd
Pinehurst NC 28374
910-420-8106
srrfan1401@...


Scott H. Haycock
 

I've used all three. I like the spot putty best, but it is black.  Be sure to prime the model or the black may affect your finish color. 

Scott Haycock
Modeling Tarheel country in the Land of Enchantm
ent

On 05/17/2021 9:14 AM Claus Schlund &#92;(HGM&#92;) <claus@...> wrote:
 
 
Hi List Members,
 
It has been a few years since I did a project that needed any putty to smooth a joint between two sections of a plastic model.
 
When I pulled out my favorite tube of putty (labeled "TAMIYA PUTTY BASIC TYPE") I found it had hardened up like a rock inside the tube!
 
Oh well, I thought. I don't like Squadron putty nearly as much, but I do have a tube already and so guess I will have to use it. I opened my tube labeled SQUADRON FAST DRYING WHITE PUTTY and it is also hardened, altho not as badly as the Tamiya putty.
 
Clearly I'm gonna have to buy a new tube of some kind of putty, so I'm looking for ideas regarding what other people use. Do you have a favorite? Pluses and minuses of each? Any help regarding gotchas and/or techniques? How about using automotive spot putty from a big box store - something like Bondo glazing and spot putty - does anyone use that?
 
Opinions...
 
Thanks in advance for your thoughts on the topic
 
Claus Schlund
 


Steve Summers
 

I make my own putty by dissolving leftover styrene sprues in n-Butyl Acetate (Tamiya extra thin cement is 50% Acetone 50% n-Butyl Acetate).  You can also use MEK to dissolve but it dries a little faster and can ‘string’ easier.  The advantage is the putty when dry is just styrene and with a little effort you can find and use any color styrene sprues.  Cut the sprues into small pieces, put in an old cleaned paint bottle, add liquid to cover the sprues.  You can add more sprues to thicken or more likely, add more liquid when it is too thick or ‘strings’.  Works very well on styrene models as the putty files, sands, and paints just like the model parts.


On May 17, 2021, at 11:30 AM, Scott H. Haycock <shhaycock@...> wrote:


I've used all three. I like the spot putty best, but it is black.  Be sure to prime the model or the black may affect your finish color. 

Scott Haycock
Modeling Tarheel country in the Land of Enchantm
ent

On 05/17/2021 9:14 AM Claus Schlund &#92;(HGM&#92;) <claus@...> wrote:
 
 
Hi List Members,
 
It has been a few years since I did a project that needed any putty to smooth a joint between two sections of a plastic model.
 
When I pulled out my favorite tube of putty (labeled "TAMIYA PUTTY BASIC TYPE") I found it had hardened up like a rock inside the tube!
 
Oh well, I thought. I don't like Squadron putty nearly as much, but I do have a tube already and so guess I will have to use it. I opened my tube labeled SQUADRON FAST DRYING WHITE PUTTY and it is also hardened, altho not as badly as the Tamiya putty.
 
Clearly I'm gonna have to buy a new tube of some kind of putty, so I'm looking for ideas regarding what other people use. Do you have a favorite? Pluses and minuses of each? Any help regarding gotchas and/or techniques? How about using automotive spot putty from a big box store - something like Bondo glazing and spot putty - does anyone use that?
 
Opinions...
 
Thanks in advance for your thoughts on the topic
 
Claus Schlund
 


Todd Sullivan
 

The problem I have had with most putties is that they shrink as they dry.  So it's like doing drywall (sheetrock) mud work: add some, sand some, add some, sand some ... repeat.  I used to use something named Liquid Steel, since it seemed to have smaller shrinkage.  Not sure if it is available nowadays.

Todd Sullivan


Tim O'Connor
 

Steve

George Bishop (Accupaint/Accucals) used to do this as well. You can layer this as well to create
reasonably large structures. He built up an entire "nose section" for a turbo train model he made and
it was perfectly sculpted, solid polystyrene when he was finished.

n-Butyl Acetate is good for bonding ABS plastics, so that's good to know about the Tamiya. :-)

Tim O'Connor


On 5/17/2021 11:42 AM, Steve Summers via groups.io wrote:
I make my own putty by dissolving leftover styrene sprues in n-Butyl Acetate (Tamiya extra thin cement is 50% Acetone 50% n-Butyl Acetate).  You can also use MEK to dissolve but it dries a little faster and can ‘string’ easier.  The advantage is the putty when dry is just styrene and with a little effort you can find and use any color styrene sprues.  Cut the sprues into small pieces, put in an old cleaned paint bottle, add liquid to cover the sprues.  You can add more sprues to thicken or more likely, add more liquid when it is too thick or ‘strings’.  Works very well on styrene models as the putty files, sands, and paints just like the model parts.



--
Tim O'Connor
Sterling, Massachusetts


Tim O'Connor
 


I have done 'finish work' with both thin CA, and liquid clear acrylic (e.g. Future) which can nicely
fill in some of the shrinkage cracks that result after the putty dries. Applied in thin layers with a fine
brush.

Tim O'Connor


On 5/17/2021 11:48 AM, Todd Sullivan via groups.io wrote:
The problem I have had with most putties is that they shrink as they dry.  So it's like doing drywall (sheetrock) mud work: add some, sand some, add some, sand some ... repeat.  I used to use something named Liquid Steel, since it seemed to have smaller shrinkage.  Not sure if it is available nowadays.

Todd Sullivan

--
Tim O'Connor
Sterling, Massachusetts


Nelson Moyer
 

Does Bondo shrink when it dries? Can it handle expansion and contraction without cracking? I’m looking of a product to fill in the irregularities in a 0.080 in. styrene backdrop splice where I put too much pressure on the splice plate behind the butt joint, creating a slight trough on either side of the splice plate when viewed from the front of the backdrop.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of O Fenton Wells
Sent: Monday, May 17, 2021 10:27 AM
To: main@realstmfc.groups.io
Subject: Re: [RealSTMFC] putty to smooth a joint between two sections of a plastic model

 

I use a Bondo auto putty from WalMart.  I know all the purists will poo poo this but it works for me and it lasts a long time.

Just say'in

Fenton

 


Craig Zeni
 

My first choice is to cut carefully enough to avoid putty; if I can get the joint tight so that when apply styrene cement that some softened plastic smooshes up from the joint, that usually means no filler needed.  But.. 

Squadron shrinks.  Tamiya is good stuff, the Mr Hobby Mr White Putty is excellent.  In the past I've used Dupont Blue Acryl auto putty - great stuff.  Mr Hobby also makes Mr Dissolved Putty.  It's a styrene soup/goop like Tim described.  Great stuff and to my mind superior to tube putty as it's harder than tube putty so it sands like the surrounding plastic.


Wallace Steinbrecher
 

Claus,

I use the Bondo spot putty and am very happy with it.  Dries quickly, sands well and does not show any texture after painting.

Regards,
Wallace 

On Mon, May 17, 2021 at 9:14 AM Claus Schlund &#92;(HGM&#92;) <claus@...> wrote:
Hi List Members,
 
It has been a few years since I did a project that needed any putty to smooth a joint between two sections of a plastic model.
 
When I pulled out my favorite tube of putty (labeled "TAMIYA PUTTY BASIC TYPE") I found it had hardened up like a rock inside the tube!
 
Oh well, I thought. I don't like Squadron putty nearly as much, but I do have a tube already and so guess I will have to use it. I opened my tube labeled SQUADRON FAST DRYING WHITE PUTTY and it is also hardened, altho not as badly as the Tamiya putty.
 
Clearly I'm gonna have to buy a new tube of some kind of putty, so I'm looking for ideas regarding what other people use. Do you have a favorite? Pluses and minuses of each? Any help regarding gotchas and/or techniques? How about using automotive spot putty from a big box store - something like Bondo glazing and spot putty - does anyone use that?
 
Opinions...
 
Thanks in advance for your thoughts on the topic
 
Claus Schlund
 


Schuyler Larrabee
 

The late Greg Martin recommended, for model joints, Hard as Nails, a Sally Hansen product you can find at your local drug store.  It is not as hard as styrene and therefore sands away before you get to the base material.  I have used it on plastic joints and also on some unfortunate joints in brass models.  Works very well.

 

Schuyler

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Wallace Steinbrecher
Sent: Monday, May 17, 2021 12:05 PM
To: main@realstmfc.groups.io
Subject: Re: [RealSTMFC] putty to smooth a joint between two sections of a plastic model

 

Claus,

 

I use the Bondo spot putty and am very happy with it.  Dries quickly, sands well and does not show any texture after painting.

 

Regards,

Wallace 

 

On Mon, May 17, 2021 at 9:14 AM Claus Schlund &#92;(HGM&#92;) <claus@...> wrote:

Hi List Members,

 

It has been a few years since I did a project that needed any putty to smooth a joint between two sections of a plastic model.

 

When I pulled out my favorite tube of putty (labeled "TAMIYA PUTTY BASIC TYPE") I found it had hardened up like a rock inside the tube!

 

Oh well, I thought. I don't like Squadron putty nearly as much, but I do have a tube already and so guess I will have to use it. I opened my tube labeled SQUADRON FAST DRYING WHITE PUTTY and it is also hardened, altho not as badly as the Tamiya putty.

 

Clearly I'm gonna have to buy a new tube of some kind of putty, so I'm looking for ideas regarding what other people use. Do you have a favorite? Pluses and minuses of each? Any help regarding gotchas and/or techniques? How about using automotive spot putty from a big box store - something like Bondo glazing and spot putty - does anyone use that?

 

Opinions...

 

Thanks in advance for your thoughts on the topic

 

Claus Schlund

 


Nelson Moyer
 

I switched from Squadron to Tamiya putty and never looked back. My first tube of Tamiya lasted several years before thickening to the point that it had to be discarded. It wasn’t completely hard, and by then I had used most of it. I keep the threads on both the tube and cap clean so there’s a good seal, and that helps prevent drying in the tube. I just started on my second tube, and that first tube lasted at least ten years.

 

I usually remove a little putty with a round pointed toothpick and put it on a glass pallet used for CA or canopy cement, and I work from the pallet. That process keeps the threads clean, and if they get some putty in them, I use acetone or lacquer thinner to clean the tube threads. Because the putty dries fast, I work with small batches at a time.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Claus Schlund \(HGM\)
Sent: Monday, May 17, 2021 10:14 AM
To: STMFC <main@RealSTMFC.groups.io>
Subject: [RealSTMFC] putty to smooth a joint between two sections of a plastic model

 

Hi List Members,

 

It has been a few years since I did a project that needed any putty to smooth a joint between two sections of a plastic model.

 

When I pulled out my favorite tube of putty (labeled "TAMIYA PUTTY BASIC TYPE") I found it had hardened up like a rock inside the tube!

 

Oh well, I thought. I don't like Squadron putty nearly as much, but I do have a tube already and so guess I will have to use it. I opened my tube labeled SQUADRON FAST DRYING WHITE PUTTY and it is also hardened, altho not as badly as the Tamiya putty.

 

Clearly I'm gonna have to buy a new tube of some kind of putty, so I'm looking for ideas regarding what other people use. Do you have a favorite? Pluses and minuses of each? Any help regarding gotchas and/or techniques? How about using automotive spot putty from a big box store - something like Bondo glazing and spot putty - does anyone use that?

 

Opinions...

 

Thanks in advance for your thoughts on the topic

 

Claus Schlund

 


Ken Adams
 

I have a tube of Vallejo plastic putty I ordered as an experiment due to arrive tomorrow. I have found Tamiya a little messy to work with and difficult to clean the joined area.  Will report when I have tried it out.


Apparently the shortage of Vallejo products over the last few months is easing.
--
Ken Adams
Still in splendid Shelter In Place solitude, about half way up Walnut Creek
Owner PlasticFreightCarBuilders@groups.io


Tony Thompson
 

     I changed long ago from Squadron to Tamiya, better qualities all around. I once made up a batch of the "styrene putty" from sprues, worked okay, wasn't wonderful. Maybe I need more experience to recommend it fully, but I recall Richard Hendrickson hadn't much liked it either. Maybe we didn't make it right.

Tony Thompson




Jared Harper
 

Automobile spot putty from an auto supply store.  I have been using it for years.  I use it on plastic, metal and wood.


Lester Breuer
 

I stopped using Squadron Green long ago as in my opinion worked ok only if a new opened  tube.   I use MEK Goop made up with scrap styrene plastic and MEK as already described.  If used a very fine wire applicator (photo attached) to apply.  I also use Testor’s putty in grey tube with white letteing.  The putty is white in color, applies easily and does not shrink.  If in a hurry either of these can be set quickly with an application of CA.   Both of these old school; however, work week for me.  Another old one is to fill crack with baking soda followed application of CA.   There are many new putties on the market today, some made especially for plastic, that all work well.  Just takes time to find one you are comfortable working with.
Keep Modeling,
Lester  Breuer


Jeffrey White
 

I've had good luck using JB Weld steel filled epoxy.  I imagine it's pretty similar to bondo (which I haven't messed with since I was a teenager working on cars).

Jeff White

Alma IL

On 5/17/2021 10:26 AM, O Fenton Wells wrote:
I use a Bondo auto putty from WalMart.  I know all the purists will poo poo this but it works for me and it lasts a long time.
Just say'in
Fenton

On Mon, May 17, 2021 at 11:14 AM Claus Schlund &#92;(HGM&#92;) <claus@...> wrote:
Hi List Members,
 
It has been a few years since I did a project that needed any putty to smooth a joint between two sections of a plastic model.
 
When I pulled out my favorite tube of putty (labeled "TAMIYA PUTTY BASIC TYPE") I found it had hardened up like a rock inside the tube!
 
Oh well, I thought. I don't like Squadron putty nearly as much, but I do have a tube already and so guess I will have to use it. I opened my tube labeled SQUADRON FAST DRYING WHITE PUTTY and it is also hardened, altho not as badly as the Tamiya putty.
 
Clearly I'm gonna have to buy a new tube of some kind of putty, so I'm looking for ideas regarding what other people use. Do you have a favorite? Pluses and minuses of each? Any help regarding gotchas and/or techniques? How about using automotive spot putty from a big box store - something like Bondo glazing and spot putty - does anyone use that?
 
Opinions...
 
Thanks in advance for your thoughts on the topic
 
Claus Schlund
 


--
Fenton Wells
250 Frye Rd
Pinehurst NC 28374
910-420-8106
srrfan1401@...


Dennis Storzek
 

I'm not sure JB Weld is what Nelson wants to use on a vertical joint on the backdrop, in my experience it tends to run or slump. I would go with one of the two part polyester auto body fillers; Bondo is one name but there are others. Two part fillers have minimal shrinkage, whereas the single component "spot putty" will shrink as the solvent evaporates.  The two part fillers may be a bit tough to sand when used on styrene, since they are as hard or harder. In which case, use the two part filler to fill the depression, and the knife a thin coat of the spot putty (also known as glazing putty) over the top and sand that smooth.

Dennis Storzek


Nelson Moyer
 

I used Tamiya putty on the butt joint crack, and it sanded smooth without any evidence of opening up after four years of expansion and contraction. Ambient temp in the basement ranges from 60° in winter to 76° in summer, and the backdrop is two 4x8 sheets of 0.08 in. styrene plus another 83 in. long piece of styrene. The backdrop is coved vertically at the top, covering the shelf brackets and attached to the ends of the brackets. I calculated the thermal expansion for 23 ft. of styrene at about ¼ in. at my temperature extremes. The backdrop creaks with short term temperature changes due to the fluorescent lights and also during seasonal changes.

 

I want a product that sands like styrene, so two part hard drying products aren’t acceptable. Ideally, the product should sand like drywall compound. I primed the backdrop with light gray Krylon Fusion, and sanding marks are evident at the joints. The final sky paint is latex, which I expect will fill minor surface imperfections from sanding.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Dennis Storzek
Sent: Monday, May 17, 2021 5:40 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] putty to smooth a joint between two sections of a plastic model

 

I'm not sure JB Weld is what Nelson wants to use on a vertical joint on the backdrop, in my experience it tends to run or slump. I would go with one of the two part polyester auto body fillers; Bondo is one name but there are others. Two part fillers have minimal shrinkage, whereas the single component "spot putty" will shrink as the solvent evaporates.  The two part fillers may be a bit tough to sand when used on styrene, since they are as hard or harder. In which case, use the two part filler to fill the depression, and the knife a thin coat of the spot putty (also known as glazing putty) over the top and sand that smooth.

Dennis Storzek

 


Robert kirkham
 

You could throw a bunch of scrap styrene into a jar of solvent cement and create a styrene putty.  It takes a while to harden, but once hard, sands just like the sheet styrene.  I’ve used it in all sorts of applications - very stable.  

Rob

On May 17, 2021, at 3:59 PM, Nelson Moyer <npmoyer@...> wrote:

I used Tamiya putty on the butt joint crack, and it sanded smooth without any evidence of opening up after four years of expansion and contraction. Ambient temp in the basement ranges from 60° in winter to 76° in summer, and the backdrop is two 4x8 sheets of 0.08 in. styrene plus another 83 in. long piece of styrene. The backdrop is coved vertically at the top, covering the shelf brackets and attached to the ends of the brackets. I calculated the thermal expansion for 23 ft. of styrene at about ¼ in. at my temperature extremes. The backdrop creaks with short term temperature changes due to the fluorescent lights and also during seasonal changes.
 
I want a product that sands like styrene, so two part hard drying products aren’t acceptable. Ideally, the product should sand like drywall compound. I primed the backdrop with light gray Krylon Fusion, and sanding marks are evident at the joints. The final sky paint is latex, which I expect will fill minor surface imperfections from sanding.
 
Nelson Moyer
 
From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Dennis Storzek
Sent: Monday, May 17, 2021 5:40 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] putty to smooth a joint between two sections of a plastic model
 
I'm not sure JB Weld is what Nelson wants to use on a vertical joint on the backdrop, in my experience it tends to run or slump. I would go with one of the two part polyester auto body fillers; Bondo is one name but there are others. Two part fillers have minimal shrinkage, whereas the single component "spot putty" will shrink as the solvent evaporates.  The two part fillers may be a bit tough to sand when used on styrene, since they are as hard or harder. In which case, use the two part filler to fill the depression, and the knife a thin coat of the spot putty (also known as glazing putty) over the top and sand that smooth.

Dennis Storzek