Sako S20 Cerakote issue

[Gab]

Hi All,

General query for you and your experience, bought a Sako S20 308 and the first day I took the rifle home after a couple of zeroing sessions with different ammo while cleaning found out the muzzle cerakote is peeling off as per picture below:



and the base of the thread as well.



Being discussing with the dealer for more than two months and GMK is coming back stating that this as wear and tear and is asking for money to get it fixed.

Rifle has shot at the range from the retailer in two ocassions, 18 rounds 123g sako factory ammo and 16 round of 150g S&B with stalon mod fitted. Two sessions in different weeks and these shots spreaded over one hours and no more than 3 round at "once", letting it cool a bit by removing the bolt.

I would appreciate your advice and experience and whether this is normal but looking a used rifles and so on can't see this in the S20s.

TIA.

 

[wytonpjs]

FWIW, I believe I have one of the first S20 in .308 Win, bought 28 Sep 2020. Since then, its had a hard life stalking repeatedly up in Scotland as well as in England. Certainly well North of 1000 rounds through it and probably double - conservatively over 300 animals. I've attached a couple of quick photos of the muzzle which on mine, was I believe never Cerakoted. The only issue I have had and actually, its not actually caused any issues in use whatsoever, is the shocking thread cutting!



I've posted on here before about poor Cerakoting inside the receiver in a Tikka T3X Wideland Veil - similar issue with GMK who said nothing wrong with it whilst Cerakote themselves said it was poor surface preparation. Like my issue on that rifle, it was cosmetic and with the bolt closed, you didn't see it and I'd suggest the same applies with your crown given the mod fitted. We both know that its there, but it doesn't affect the rifle practically.

 

[Eric the Red]

Are you sure that's Cerakote and not carbon on the crown? It would be normal for the threads to be cerakoted as well for a complete coating, not in patches. Personally I'd want a shiny crown anyway. I'd apply some carbon cleaner and see what comes off.
Cerakote is only as hard as the surface underneath it and is not a complete scratchproof/wearproof coating. I'm not saying it should do that, but it is very easy to mark Cerakote. And it wears over time.

 

[Gab]

Are you sure that's Cerakote and not carbon on the crown? It would be normal for the threads to be cerakoted as well for a complete coating, not in patches. Personally I'd want a shiny crown anyway. I'd apply some carbon cleaner and see what comes off.
Cerakote is only as hard as the surface underneath it and is not a complete scratchproof/wearproof coating. I'm not saying it should do that, but it is very easy to mark Cerakote. And it wears over time.

Hello Eric, thanks for your message, it is not carbon built but the cerakote coming off. The rifle is "two days old" so can undestand after a few hundred rounds and tough weather that might show symptoms of wear.

 

[Jagged77]

I think that’s fair wear and tear - I wouldn’t want the face ceracoted in the first place. It’s going to build up with carbon anyway. End of the day the muzzle is subjected to the pressures of firing and the threading has a can and thread protector on and off, it’s bound to wear. I’d want bare metal and keep them clean.

 

[Gab]

I think that’s fair wear and tear - I wouldn’t want the face ceracoted in the first place. It’s going to build up with carbon anyway. End of the day the muzzle is subjected to the pressures of firing and the threading has a can and thread protector on and off, it’s bound to wear. I’d want bare metal and keep them clean.

Hello Jagged, thanks for your message. Could you please help me to understand why you think is fair wear. Not an expert hence my request for help in first place. My understanding is that outside barrel there is no pressure but a flow of gasses at high speed, so as far as the coating has attached properly it should not come off after a few rounds, the rifle was shot in two occasions since new. Why do you prefer bare metal rather than a coating that is designed to prevent corrosion.? What do you use or apply to prevent corrosion in that area? Gun oil? gun grease? Thanks a lot.

 

[C h r i s]

A good cerakoter would not paint the crown. My Tikka T3x with the factory applied cerakote did the same, I realised it was probably accelerated by using a moderator, the hot gasses are forced back onto the crown, so it's effectively being blasted.

 

[AlexD]

Hello Jagged, thanks for your message. Could you please help me to understand why you think is fair wear. Not an expert hence my request for help in first place. My understanding is that outside barrel there is no pressure but a flow of gasses at high speed, so as far as the coating has attached properly it should not come off after a few rounds, the rifle was shot in two occasions since new. Why do you prefer bare metal rather than a coating that is designed to prevent corrosion.? What do you use or apply to prevent corrosion in that area? Gun oil? gun grease? Thanks a lot.

A bit of information about Cerakote (we apply it to hundreds of items every month, and have learnt the hard way how it comes off, or stays on).
1. Cerakote is a thin epoxy paint with ceramic particles in it. It is as strong as a very thin epoxy, and no stronger. As a thin coating, it must not be put on threads, otherwise the threads may be out of tolerance. Cerakote liquid has the same viscosity as liquids such as water or alcohol: it goes on really thin by spraying it from an airbrush gun.
2. Making Cerakote stay on, requires absolute compliance with the Cerakote process. Any deviation results in disaster. For example, if one cleans up the part with acetone after shot blasting it, before baking it, then the Cerakote will peel off when knocked - you would not expect that cleaning the part makes the bond weaker, but that is the fact. Another aspect is the shot blasting has to be done with exactly the right sized grit, and after baking check for any signs of contaminants coming to the surface: if there are, then wash in acetone in an ultrasonic bath, blast again, bake again, check again. Looking at your images, if the crown has been Cerakoted, then it has not been blasted properly, so the Cerakote will come off. I would not dream of Cerakoting the crown, because it will not last, so not sure of why the coating was applied there, especially as without heavier blasting it will come straight off.
3. There are different series of Cerakote, e.g. C Series, H Series, E Series. H is supposed to be a tough military grade coating, which we liked because it is easy to get a matt or a gloss finish just by adjusting the ratio of resin to hardener slightly, BUT it is nowhere near as tough as E Series. When buying something that is Cerakoted, check what series it is. Your barrel is not E series, just from the look of it.

My advice is to polish off the Cerakote and be happy with a shiny end to your barrel. If you really want it black, use a rust blackening, or wait for the carbon to give you your wish, or just put a moderator over it as you should do if you fancy your hearing.

 

[Jagged77]

Hello Jagged, thanks for your message. Could you please help me to understand why you think is fair wear. Not an expert hence my request for help in first place. My understanding is that outside barrel there is no pressure but a flow of gasses at high speed, so as far as the coating has attached properly it should not come off after a few rounds, the rifle was shot in two occasions since new. Why do you prefer bare metal rather than a coating that is designed to prevent corrosion.? What do you use or apply to prevent corrosion in that area? Gun oil? gun grease? Thanks a lot.

Brilliant post by AlexD above!

On the other questions, if using a mod it will create back pressure on the muzzle.

What corrosion are you expecting to see on a stainless barrel exterior? Not saying it can’t rust but I’ve never oiled any of my muzzle threads - carbon steel or stainless, just cleaned as and when.

When using a mod I want metal to metal contact on the threads and the back shoulder. I’m sure cerocoting won’t introduce much of a tolerance deviation, if any, but it’s a variable that doesn’t need to be introduced in the first place in my opinion.

 

[Ronin]

A bit of information about Cerakote (we apply it to hundreds of items every month, and have learnt the hard way how it comes off, or stays on).
1. Cerakote is a thin epoxy paint with ceramic particles in it. It is as strong as a very thin epoxy, and no stronger. As a thin coating, it must not be put on threads, otherwise the threads may be out of tolerance. Cerakote liquid has the same viscosity as liquids such as water or alcohol: it goes on really thin by spraying it from an airbrush gun.
2. Making Cerakote stay on, requires absolute compliance with the Cerakote process. Any deviation results in disaster. For example, if one cleans up the part with acetone after shot blasting it, before baking it, then the Cerakote will peel off when knocked - you would not expect that cleaning the part makes the bond weaker, but that is the fact. Another aspect is the shot blasting has to be done with exactly the right sized grit, and after baking check for any signs of contaminants coming to the surface: if there are, then wash in acetone in an ultrasonic bath, blast again, bake again, check again. Looking at your images, if the crown has been Cerakoted, then it has not been blasted properly, so the Cerakote will come off. I would not dream of Cerakoting the crown, because it will not last, so not sure of why the coating was applied there, especially as without heavier blasting it will come straight off.
3. There are different series of Cerakote, e.g. C Series, H Series, E Series. H is supposed to be a tough military grade coating, which we liked because it is easy to get a matt or a gloss finish just by adjusting the ratio of resin to hardener slightly, BUT it is nowhere near as tough as E Series. When buying something that is Cerakoted, check what series it is. Your barrel is not E series, just from the look of it.

My advice is to polish off the Cerakote and be happy with a shiny end to your barrel. If you really want it black, use a rust blackening, or wait for the carbon to give you your wish, or just put a moderator over it as you should do if you fancy your hearing.

This

You wouldn’t normally coat the crown - it’s subject to several thousand psi as the bullet exits the muzzle with gas wash

Better clean off the residual and leave clean. Bare metal

 

[Gab]

Brilliant post by AlexD above!

On the other questions, if using a mod it will create back pressure on the muzzle.

What corrosion are you expecting to see on a stainless barrel exterior? Not saying it can’t rust but I’ve never oiled any of my muzzle threads - carbon steel or stainless, just cleaned as and when.

When using a mod I want metal to metal contact on the threads and the back shoulder. I’m sure cerocoting won’t introduce much of a tolerance deviation, if any, but it’s a variable that doesn’t need to be introduced in the first place in my opinion.

Thanks, I think that wasn't clear, know that thread should be clean but after the recess from the thread back to the diameter of the barrel, at the beginning of the thread from barrel rather than muzzle...the second picture. Where the mod sits and tighten against.
Thanks for your help.

 

[C h r i s]

Ah, you mean the shoulder. My S20 didn't have that issue.

 

[wytonpjs]

Ah, you mean the shoulder. My S20 didn't have that issue.

As per my post #2 above, neither does my S20. Either they have changed the production specs or someone has not followed them correctly. As per @Ronin 's advice, best cleaned off IMHO.

 

[C h r i s]

The only issue I have had and actually, its not actually caused any issues in use whatsoever, is the shocking thread cutting!

View attachment 420958View attachment 420959

Wow, that thread is horrendous ! Don't know how you can sleep at night!

 

[AlexD]

Wow, that thread is horrendous ! Don't know how you can sleep at night!

I think it looks much worse than it is, because of reflections and the way carbon has coated the runout at the barrel end of the thread.
I can't see any chatter on it, the thread is even and angles look good. The start of it at the crown end is not perfect, but not out of the ordinary, and can be cleaned up easily if someone is niggled by it.
The OP has a rifle with a functional thread for a moderator, so just needs to polish off the Cerakote on the crown, then put a mod on it.
Let us not take the OP's joy away for his new acquisition. I am sure it will bring him a lot of joy in the future, and many deer.

 

[Bowland blades]

Especially with a moderator this will happen , its to be expected there are some seriously high temperature and hot gasses and corrosive residue left behind . Go watch a muzzle blast without a moderator in the gloaming from the side of the shooter you will get the point . The upside is Carcoat is just about the best coating on a rifle barrel . Proper Parkerizing is better for protection but few if any makers do it now

 

[Brad93]

cerakote if done correctly should be able to withstand intense heat, chemical attack and fouling.

the edge of the crown/barrel/rifling looks sharp.

any sharp edge is naturally the weak point in any sort of coating system whether that be:

Electroplating, hard chroming, thermal spray, ceramic coating, powder coat etc.

Then there is the preparation of the substrate.
for a proper bond the surface should be abraded and then thoroughly cleaned - when I worked in aerospace we DA'd sheet metal or tumbled then dipped in 7 different tanks, can't remember if it was Trichloroethane or MEK now.

 

[AlexD]

The upside is Carcoat is just about the best coating on a rifle barrel . Proper Parkerizing is better for protection but few if any makers do it now

We switched to DLC (Diamond Like Carbon) for anything that can take DLC. DLC is vastly superior to Cerakote when compared for abrasion resistance, bonding, temperature, resistance to surface marks, and pretty well every other metric. The only problem with DLC is the cost, especially if you are dealing with one-offs or low volume, or if it has a large surface area.
We still do a lot of items in Cerakote, using only E Series now, because Cerakote is cheaper, and for no other reason. If anyone wants litre sized tubs of H grade, we have a few going cheap. Colours graphite black and black.
As a quick demo for DLC, we invite people to take their car keys and try and scratch it, drop it to dink it. It leaves not a mark.
Car keys make a mess of Cerakote, and if you ask me about dinks and flakes, I have a library of photos of woe to share.

If you have a steel barrel, then old fashioned rust bluing is easily repaired, robust, and so long as you keep your guns in a dry environment, it will look good in 100 years time. I would not say the same of Cerakote. Of course, one can't rust blue stainless, so one ends up with Cerakote or DLC as the only options.

For those with steel barrels, you can get far more beauty out of a good rust blue or hot blue than any Cerakote job. If you are worried about rust, then there is a trick to stop anything rusting: just wipe it over with a clean rag dipped in a strong solution of caustic soda (i.e. caustic soda and water). The water will dry off, leaving sodium hydroxide as a very thin film. To have rust form you need either humidity + acidic conditions, or chlorine, so by making the surface alkaline one stops rust dead. If you put oil on any parts, then avoid caustic on those parts, as it will turn the oil into soap.

All oil and grease does is keep the humidity away from the steel. Putting a dehumidifier into your gun room, reduces humidity (if you remember to empty it daily), but when you take it hunting the gun gets soaked. Using caustic means that even when soaked, it does not rust.

By the way, never allow acids into your gun room, or anyone with bleach: even stainless steel guns are fitted with parts made from carbon steel.

 

[Edinburgh Rifles]

Factory Cerakote jobs are famously ****
We returned numerous guns in the past for exactly this
We also recoated a Sauer at their cost as it was going to have to go back to Germany

Distributors are becoming more like insurance companies with warranty issues
“Computer says No…..”
I am tired of fighting for warranty replacements

Insist!
Either get it replaced (ballache)
Or Get it blasted and done properly

Drop me a line if I can help
We have a Cerakote certified painter

 

[AlexD]

Factory Cerakote jobs are famously ****
We returned numerous guns in the past for exactly this
We also recoated a Sauer at their cost as it was going to have to go back to Germany

Distributors are becoming more like insurance companies with warranty issues
“Computer says No…..”
I am tired of fighting for warranty replacements

Insist!
Either get it replaced (ballache)
Or Get it blasted and done properly

Drop me a line if I can help
We have a Cerakote certified painter

You are great for standing up for your customers Ed.

We provide a lifetime no quibble warranty for our products, no matter what the user has done to the product, and this policy helps ensure staff know that if something is not right, and not picked up in production, then it will hurt a lot more later. Short warranties encourage sloppy production.

The problem in factories with Cerakote, is Cerakote does not suit robots, and production staff have the highest staff turnover, so factories often make the mistake of sending one person to get certified, but then that person is allocated to supervising, or writing the factory work instructions, or he has left. Having the person himself who was certified do the whole job is the only way to do it. That person must be super exact in their work.

As I mentioned earlier, we Cerakote hundreds to thousands of parts a month (production of military underwater equipment + the odd gun part I sneak in), but only one lady does it even though we have trained five people to do it over the years - four guys and this one lady. If that lady is not in, then we reschedule coating for when she is in. When we are really busy, she does the critical tasks of the 4 UV+lights visual inspection involved in the process, alongside others who are blasting and coating. Her attitude that customers deserve nothing less than perfection is perfect for this role.

People may not appreciate to what extent Cerakote is a manually intensive process that cannot be automated reliably. One has to look at the part under UV and bright light to ensure the initial cleaning in acetone has not brought oils to the surface, and, then masking off is done by hand, followed by some skill to ensure the shot blasting is sufficiently deep, but not too deep, and has left nothing untouched anywhere you want coated - shot blasting by hand is not a fun task to do day after day. The inspection after blasting has to be done under the same UV and bright lights to see if any more oil is revealed (and if so, go right back to the beginning with acetone ultrasound bath, shot again etc, without hesitating about the time it takes). The actual painting with Cerakote is the easy part, but still takes some practice to get right, followed by curing in industrial fan ovens. Coating has to be done the same day as the blasting, so coating days tend to be 10 to 12 hours long including the clean up.

Give me DLC any day, as no blasting required, just the acetone ultrasound bath to degrease, and masking. Only problem is the cost.

By the way, due to growing sales, we have vacancies for design engineers (elec, firmware, mech, validation), toolmakers & production staff, if anyone in the Edinburgh/East Lothian area is interested, and among that intake is another person to train up to Cerakote.