Pig Tails Causes and Removal?

[the_invisible]

My Maxima's hood was repainted many years ago for rock chips. While the hood looks perfect in every way, there is one spot that has a very noticeable pig tail sanding marks on it.

How was this pig tail created? Was it created during the sanding and removal of the previous paint? Or is it created during the sanding of the new paint?

If it was simply created on the new clear coat, it should be removeable by means of wetsanding, right?

Is there a way to remove pig tails?

[Markus Kleis]

Re: Pig Tails Causes and Removal?

Pig tails are similar to a sanding tracer, but they are gauges left from compound or polish and a dual-action buffer. The pattern of movement that a DA makes creates the unique "pigtail" shape.

To remove them you just need to polish down to the lowest point of the pigtails and level the surface- just like any other scratch or swirl.

[Eddie6th]

Re: Pig Tails Causes and Removal?

The worst things for making pigtails is when sanding wood with one of those 'mouse' power tools.

[the_invisible]

Re: Pig Tails Causes and Removal?

Mark, thanks for the explanation on how these marks are created. However, my question asks if these markings occur on the clear coat or somewhere below the clear coat, where I have no chance of correcting them. I guess I am asking more about the nature of this symptom rather than the cause of it.

I remember reading a post on MOL about some guy who had his bumper fixed for dirt cheap, and ended up with tons of pig tails, and that those pigtails were removed by wetsanding. All the posts about pigtails seem to be on the new clear coat, and not somewhere imbedded in the metal, primer, base coat. I will ask the bodyshop tomorrow if they would fix those pigtails they created 5 years ago. If they wouldn't, I would ask them how much clear I have to play with.

And yeah, Eddie. I have a Ryobi dual action sander for wood. It's great for removing paint on my fence. Makes the rough wood ultra smooth! Even with pigtails, the surface is extremely smooth. Honestly, some pigtails on wood is not even noticeable. Of course, I am not using my Ryobi to build delicate furniture.

[Eddie6th]

Re: Pig Tails Causes and Removal?

Ryobi are popular over here.Don't hear about it much on the forum.

A DA sander is great for sanding.I like the festool rotex...but 600 euros! I've still got a metabo mouse...They're okay,i suppose.....more like Mickey Mouse!

Another member had that model....FestoolRotex150 i think? Said it was great for sanding,but as a polisher wasn't so good. I don't know why? The tech.spec. is much the same as any DA,except it has a larger orbit diameter.Also it can be locked,to behave as a direct drive. I don't own a DA,so I don't know?

[PorscheGuy997]

Re: Pig Tails Causes and Removal?

Pigtails can also be caused by DA sanding from the body shop. DA sanding takes less time and is not as messy, but it is very easy to instill pigtails.

Here are some things that can cause pigtailing:
-Grit, dust, or other foreign particles under the abrasive
-Clogged abrasives
-Letting the disk rotate - you do not want the disk to be spinning at all.

More than likely, the shop used a DA sander to level the paint and didn't quite remove every last scratch. It may be necessary to sand the hood again if the marks are really deep. Otherwise, you can polish out the scratches as normal.

[the other pc]

Re: Pig Tails Causes and Removal?

Like Chris said, body shops rely heavily on DA sanders.

They can be used on every stage of a finish, from the bare metal up to the topcoat.

If your pigtails are in plastic filler, primer or base coat you’re out of luck. The only way to get rid of them is to sand down and re-spray.

If they’re in the topcoat and aren’t too deep they can be sanded and/or buffed.


pc.

[the_invisible]

Re: Pig Tails Causes and Removal?

Just wetsanded the hood of my daily driver Nissan Maxima and removed as much pig tails as I could see. Some are not visible so I gave them a light sanding and moved on. The severe ones in noticeable areas are fully removed. Also gave the entire hood some wetsanding to match the smoother surfaces...

[Eddie6th]

Re: Pig Tails Causes and Removal?

Nice work.It looks like a mirror!

Pigtails are horrible things! (on surfaces....no offence to any boars,hogs or pigs!)

[SHYNEMAN123]

Re: Pig Tails Causes and Removal?

Pigtails can also be caused by DA sanding from the body shop. DA sanding takes less time and is not as messy, but it is very easy to instill pigtails.

Here are some things that can cause pigtailing:
-Grit, dust, or other foreign particles under the abrasive
-Clogged abrasives
-Letting the disk rotate - you do not want the disk to be spinning at all.

More than likely, the shop used a DA sander to level the paint and didn't quite remove every last scratch. It may be necessary to sand the hood again if the marks are really deep. Otherwise, you can polish out the scratches as normal.

Chris is dead on!!!!

To add to that when you are doing body work you need to follow the 100 grit rule!!!!!

If you use 80g to remove a defect you need to use 180g to remove the
80g sand scratches , Than 220g and than 320g. You should never prime over anything less than a 320g. After priming you can dry sand with 500g ot wet with 600g Than your ready for sealer and paint.

As paint cures from the out side in it shrinks into the repair as it shrinks the clear can mirror the underlying marks, so the finner the prep the lees the top coat has to shrink into.

In a lot of cases when enough clear is applied it will bridge the marks and they can be wet or dry sanded out and than buffed .