McMillan surface blem: Self-Induced or QC issue?

[Wallaback]

Hey there Hide,

So I recently impulse-purchased a McMillan A4 from their Ready-to-Ship section, knowing full well that I wasn't suuuper convinced by the transition paintjob it came in - but it had all the features I wanted in the inlet I wanted, so I figured what's the harm.

Once it showed up, my suspicion was confirmed and I didn't waste any time dropping it off with my local cerakote shop to give it a classic green makeover.

When I picked the stock back up, I noticed some pretty egregious surface blemishes that I hadn't noticed when the stock first showed up (see pictures).

My question for you:

Is there some sort of incompatibility between the Cerakote process and McMillan fibreglass stocks that I wasn't aware of and I did this to myself, or was there a QC issue with the stock that I didn't see when I received it?

If I don't want to ship it back to McMillan to fix, how would you recommend going about fixing the blemishes, if at all?

 

[pmclaine]

It’s a fiberglass stock.

I don’t know maybe there is a reason stuff falls into the ready to ship section.

Lots of very desirable McMillan stocks evidence the laid fiberglass.

If that was going to be an issue for you I might have went another route.

 

[cas6969]

If you didn't buy a Blem, did your cerakote guy remove some top coat in the prep?

 

[corsairpilot62]

Dude! Its a mcmillan damn thing is bomb proof. Who fucking cares if its a little ugly. Spray Paint that bitch up and get shooting!

 

[Coejro]

It looks like your cerakote guy sandblasted it

 

[Hennig]

Dude! Its a mcmillan damn thing is bomb proof. Who fucking cares if its a little ugly. Spray Paint that bitch up and get shooting!

These comments are so stupid. It’s like buying a new car covered in paint chips and being told “well it’s gonna happen anyway, who cares”.

Hard to tell, if the cerakote guy assholed that by blasting it with high pressure, you can expose the weave.

I’ve also seen some pretty average factory finishes that had to go back for repair. Hard to know now though…

 

[ma smith]

It’s a fiberglass stock ... If that was going to be an issue for you I might have went another route.

so the thing here that really sucks is just the timing,
AFAIK, the cost of fixing is minimal, but now its paint 2x...

I'm sypathetic to the op tho and think he should fix it,
if the belm interferes with the shooting/grip.

If thats the case, I'd also be sympathetic to op
asking OEM to cover 1 of the 2 paint jobs,
since its not even a blem but a functional defect.

Keep in mind, even if they agree,
that might also take 6months ...

curious what other people think.

 

[Coejro]

Honestly the fact you didn’t notice before you sent it off makes me strongly lean on your cerakote guy. I’ve owned a lot of McMillan stocks, and am fully aware of their mold lines, exposed fiberglass, etc.

That looks excessive, and I doubt it QC’d out like that. Sure, stuff gets missed, etc. but 3 things make me think sandblasting:

1. The flush cups are drilled pretty much last. They always have clean edges (with occasional minor chipping). The smoothing over of the stock material near the flush cups is indicative of sandblasting.
2. The texturing transition is usually sharp. Especially the web texture looks blurred and almost flattened at the transition line.
3. The bubbles you see are common in all fiberglass laid items. McMillan fills them in pretty religiously. Sandblasting would impact these heavily since it’s a different material so more prone to impact than the homogenous material around it.

 

[Terry Cross]

^^^ This ^^^

McMillan has definitely had a decline in QC since being bought BUT this is not their fault.

Their paint finishes are not as durable long term as their molded in gel-coat patterns however their poly-paint finish sticks pretty damned good on the primed stock shell.

The shop that handled your CeraKote removed the original McMillan applied poly-paint finish with an aggressive abrasive.
My money would be on them doing that work of art with a belt sander.

They ran right through the poly-paint and kept going through the top gelcoat and into the fiberglass cloth that McMillan uses to mold the shell. No fucks given. They needed to get it stripped in a hurry and well, you know. . time is money....

Definitely not McMillan.
Definitely Mr. CeraKote pants.

.

 

[carbonbased]

Definitely Mr. CeraKote pants.

Haha awesome phrase!

 

[AirgunnerPCP]

To me that doesn't look like that was done with an abrasive. If done properly, any voids that are filled wouldn't exhibit breakout like that.

Not knowing what gel coat or resin system they use, my hunch is that they turned up the oven to cure the Cerakote too high for the stock. Then you get the gel coat exhibiting excessive shrinkage which shows the fabric weave.

3. The bubbles you see are common in all fiberglass laid items. McMillan fills them in pretty religiously. Sandblasting would impact these heavily since it’s a different material so more prone to impact than the homogenous material around it.

Also a side note, when I first got my manners I was disappointed in the quality of the layup. There are a few voids in it which I wouldn't expect from something that costs as much as it does. Other than the small blemishes, it's a fantastic stock.

 

[Ckleeves]

What’s going on with the recoil pad? Hard to tell in the pic but it almost looks like it shows evidence of sand blasting?

 

[jetmd]

Curing oven too hot, excessive removal techniques or both.

As stated above.

 

[Terry Cross]

To me that doesn't look like that was done with an abrasive. If done properly, any voids that are filled wouldn't exhibit breakout like that.

I believe that is simply the open voids in the weave of the fiberglass cloth that they sanded down to.
There are tons of voids and air pockets in almost all of the shells they mold.
They spend considerable time patching and blending the surface voids before painting.

If molded-in gelcoat pattern, they do that plus have to color blend for decent cosmetics. That is why they started charging an extra premium for molded-in gelcoat patterns now.

We are constantly having to finish breaking out blisters and voids right under the surface, fill them and patch them. The subsurface air pockets are especially notorious around corners and hard curves because of their mold process. Definite possibility that the void/crack shown behind the rear tang was there when the stock was shipped but it had solid layer of gelcoat covering it.

Not knowing what gel coat or resin system they use, my hunch is that they turned up the oven to cure the Cerakote too high for the stock. Then you get the gel coat exhibiting excessive shrinkage which shows the fabric weave.

If they brought that stock up to a high enough temp to compromise the already cured epoxies in the shell (excessive shrinkage), the whole stock would have been compromised/warped/cracked. Once the cured epoxy gets hot enough to move, the glass fabric would certainly try to float and delaminate.

My opinion would be that oven heat can certainly be a huge problem, it was not this problem.

I have a few totaled McMillan stocks laying around the shop. If I can find time next week, I will try to sand some areas down as well as heat it up to 400-500*F and take some before / after pics.

@Short-bus does bunch of CeraKote jobs on glass stocks.
He would probably be a good resource to view the images and give his input.

 

[Terry Cross]

Hard to tell in the pic but it almost looks like it shows evidence of sand blasting?

Abrasive blast would also give the same results as shown above! Good call.

In fact now that you brought it up, that might be my new #1 guess and pushing the sander to #2.

Of course Short-bus might still come in here and prove we are all way off base.

.

 

[AirgunnerPCP]

I believe that is simply the open voids in the weave of the fiberglass cloth that they sanded down to.
There are tons of voids and air pockets in almost all of the shells they mold.
They spend considerable time patching and blending the surface voids before painting.

Done properly, there are no voids in the weave of the fiberglass. If that was common place, composites would be a whole lot worse to make things out of. Even hand layups shouldn't produce parts that are filled with voids.

But that's kind of my point though, I don't think their process is very good based on the results.

If they brought that stock up to a high enough temp to compromise the already cured epoxies in the shell (excessive shrinkage), the whole stock would have been compromised/warped/cracked. Once the cured epoxy gets hot enough to move, the glass fabric would certainly try to float and delaminate.

I disagree with this. Gel coat definitely can shrink enough to expose the weave without compromising the laminate. And it takes less heat than you'd think. In the high end marine industry, finishers are sometimes polishing out orange peel in the gel coat of the boat up until it leaves the factory. It continues to cure (and shrink) when left in sun. EDIT: I could be wrong but I'm pretty sure the epoxy would burn off before it loses enough viscosity for fabric to delaminate. It could certainly get hot enough to warp the part though.

Granted I dunno what sort of process or materials or what their laminate design is so I'm just speculating based on the results. I'd definitely like to see how those samples turn out though.

 

[D̷e̷v̷i̷l̷D̷o̷c̷A̷Z̷]

That should be reported to local law enforcement. It’s a crime what “mr cerakote pants” did!

 

[Short-bus]

Oh geez, another sub-standard painter strikes again.

That stock has had the ever living hell blasted out of it. The blasting media will remove the gel coat and/or resin down to the fiberglass or carbon fiber fibers. It's repairable, can be restored, but you need to kick the guy that did this in the dick. If he did this to the stock and gave it back to you like this, there's not a chance that he knows how to repair 'em.

I've repaired several hundred stocks now that have had various stages of damage. Done several that were FAAAAAR worse than yours.

I can restore it, and i'll enjoy restoring it. If you want references, call Tom at Manners stocks, he'll confirm that i'm very capable. Terry tagged me, he's familiar with my work.

Branden

 

[Short-bus]

To me that doesn't look like that was done with an abrasive. If done properly, any voids that are filled wouldn't exhibit breakout like that.

Not knowing what gel coat or resin system they use, my hunch is that they turned up the oven to cure the Cerakote too high for the stock. Then you get the gel coat exhibiting excessive shrinkage which shows the fabric weave.



Also a side note, when I first got my manners I was disappointed in the quality of the layup. There are a few voids in it which I wouldn't expect from something that costs as much as it does. Other than the small blemishes, it's a fantastic stock.

I know manners stocks that are in too hot of an oven will split down the middle. The heat acts like water freezing in a glass in the freezer. Expands and breaks the glass, or in this case, pushes the 2 halves of the stock apart. I'm pretty sure a Mcmillan will do the same thing, but I haven't personally seen that. I've heard that HS Precisions and B&C's fill will burst out of any gap it finds in the seems and blowout like a broccoli floret. I'm very careful with part temps to avoid this because as good as I am at fixing stocks that have received heat damage, I don't like doing it when it's my fault.

Branden

 

[AirgunnerPCP]

I know manners stocks that are in too hot of an oven will split down the middle. The heat acts like water freezing in a glass in the freezer. Expands and breaks the glass, or in this case, pushes the 2 halves of the stock apart. I'm pretty sure a Mcmillan will do the same thing, but I haven't personally seen that. I've heard that HS Precisions and B&C's fill will burst out of any gap it finds in the seems and blowout like a broccoli floret. I'm very careful with part temps to avoid this because as good as I am at fixing stocks that have received heat damage, I don't like doing it when it's my fault.

Branden

So when you say the stock splits in half is the core expanding and splitting the laminate? I'm really curious about their materials and process now lol

 

[powdahound76]

Funny to me some guy who knows Jack about materials and process arguing with a guy (Mr Cross) who designed his own stock to be built by McMillan for him.


OP, contact Branden and kick Mr Cerakote Pants in the nuts.
Honestly he should pay for your full repair or a new stock.

 

[AirgunnerPCP]

Funny to me some guy who knows Jack about materials and process arguing with a guy (Mr Cross) who designed his own stock to be built by McMillan for him.


OP, contact Branden and kick Mr Cerakote Pants in the nuts.
Honestly he should pay for your full repair or a new stock.

Hey I'm just trying to learn something here lol I for sure don't know everything and still am learning everyday. I do know a bit of something about composite materials and processes though having designed composite parts, tools and processes for a living across a few industries. Including some parts that have a similar ish construction to rifle stocks.

 

[pmclaine]

Op I stand corrected and apologize for my first post.

Of the two or three custom order McMillans I have down stairs I can go over them with a critical eye and find stuff not aesthetically eye pleasing but I buy them for function and history so it’s never bothered me.

My understanding of how they are made (wild ass guessing) is you have a split mold and someone is brushing in release color gel, strips of glass and resin by hand. Each will be unique.

Experts have spoken and identify it as follow on damage - again my apologies and I hope you get what you seek.

 

[Jackalope]

Definitely blasted the body filler out of those areas. It’s much softer than the surrounding fiberglass.

 

[Charger442]

What’s going on with the recoil pad? Hard to tell in the pic but it almost looks like it shows evidence of sand blasting?

good eye. that's more concerning than the fiberglass but i think its the smoking gun of the stock being blasted

 

[Short-bus]

Op I stand corrected and apologize for my first post.

Of the two or three custom order McMillans I have down stairs I can go over them with a critical eye and find stuff not aesthetically eye pleasing but I buy them for function and history so it’s never bothered me.

My understanding of how they are made (wild ass guessing) is you have a split mold and someone is brushing in release color gel, strips of glass and resin by hand. Each will be unique.

Experts have spoken and identify it as follow on damage - again my apologies and I hope you get what you seek.

You're spot on on one process of how they're made. There's pre-preg carbon that gets used a lot now that just involves pushing the carbon into the mold, but the split mold process is how they're made.

I've been out of the manufacturing side of the industry for a decade now, so there are new techniques and method that have been developed that I don't know about, so I wouldn't consider myself very knowledgable on the matter anymore.

Branden

 

[jetmd]

@Short-bus you need to get back to painting stuff, or fire up the Kart!

 

[Short-bus]

@Short-bus you need to get back to painting stuff, or fire up the Kart!

I'm taking the kart out for some laps tomorrow. I wanted to go today but the track is closed the 3rd Friday and Saturday of the month.

After practice, I'm taking the front end apart to cerakote a bunch of parts on it lol.

Branden

 

[Wallaback]

good eye. that's more concerning than the fiberglass but i think its the smoking gun of the stock being blasted

What you’re seeing there is actually just the spacer system. Spacer and buttstock were removed when I dropped off the stock.

 

[Mike Casselton]

I could do a much nicer job than the OP got if was totally blindfolded and only used my left hand.

That stock got sand or soda blasted for sure.
The spacer on the butt gets blended by MacMillan. It doesn't get a valley blasted at the transition between the spacer and the butt pad.

I hope like hell you didn't pay much for that kind of work.

This should be a lesson for everyone that saving a few bucks isn't saving shit.