# Mirka Shark Blade / Denibber / How to use?



## jure5gtt (Jun 14, 2017)

*Mirka Shark Blade / Denibber / How To Use?*

Hi everyone,

Have been lurking for ages and joined forum some time back but never wrote anything since vast majority of forum population do not have much to learn from me or my "rich" experience in detailing. :speechles

I'm not complete noob and have tried a lot of products and DIY techniques related to car care and detailing.

I decided to write my first topic, after extensive search on this forum and research on other websites, about cutting method step in stone chip repair procedure with touch up paint.

Theoretically and from own experience I know how to clean surface with IPA, how to apply base coat, build up clear coat, how to leave clear coat layer with a blob that needs to be flattened and now I'm stuck and need your help. On my previous car I tried to flat the area with wet sanding method (small piece of P2000 on the tip of pencil with rubber eraser on top) but I wasn't quite patient and tried to redo repaired area 3 times and managed to achieve strikethrough. Touch down!:buffer:

With my new car, I decided to go for little more safer approach in flattening/cutting/shaving raised areas and bought Mirka Shark Blade. I did not go after Festool Denibber (LZK-HM 497525) not because it's bit more expensive but found info here that Mirka is more beginner friendly and sufficient for hobby use regarding tool life span.

My first and main inquiry is based on how to properly hold Mirka Shark Blade. I found few instructional videos for Festool Denibber and how to place it to rest on the matching cord to achieve optimal cutting angle. On other hand, haven't found any video instruction or user manual for proper Mirka Shark Blade handling. It is, obviously, differently shaped and cannot be laid down on the cord but you rather need to hold it in dominant hand and make slightly curved pushing movement. I place Mirka Shark Blade in hand similar to stone that you intend to throw to make water ripples.

In this moment few questions arise:

1.	Is upper mentioned "throwing stone" correct positioning of tool in the hand?
2.	If it is not - please advise how to hold properly?
3.	Do I make pulling or pushing hand movement?
4. How long hand movements do I need to make to produce momentum (sufficient cutting force)? 
4.	What is approximate optimal angle of tool placed on the surface?
5.	How much of pressure (weight) on surface do I need to apply when making cutting movements?

I attached two photos of the area that I started to cut but stopped after few cuts because I noticed slight cutting marks (blurring) on surrounding non touched-up area. Better safe than sorry since factory clear on BMW F30 is approx 90µ. Is this OK and can I relatively safely continue with flattening the area?



















Many thanks in advance,

Jure


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## neilmcl (Mar 26, 2010)

IS this the tool


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## Sicskate (Oct 3, 2012)

I made that video clip many years ago now, infact I still use the same shark blade daily. 

One issue you'll notice is that they are super sharp to start with, after use it will blunt off and become nice to use. 

Also, you need to flat the clip after shaving off, so a slight scuff is fine as it'll probably sand out. 

Sent from my FRD-L09 using Tapatalk


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## jure5gtt (Jun 14, 2017)

neilmcl said:


> IS this the tool
> 
> Mirka paint shaving block - YouTube


Yep. Thats the tool. Saw that video few times and still do not have courage to try on my own. I tried to mirror angle and movement but not the speed and force.


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## jure5gtt (Jun 14, 2017)

Sicskate said:


> I made that video clip many years ago now, infact I still use the same shark blade daily.
> 
> One issue you'll notice is that they are super sharp to start with, after use it will blunt off and become nice to use.
> 
> ...


Thanks for your input. If I recall correctly you were the one that already warned few times that denibbers are dangerously sharp when new and was one of the reasons why I stopped what I was doing and asked for an advice. I will try to buff this blurred are and will see where I'm standing.


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## slim_boy_fat (Jun 23, 2006)

jure5gtt said:


> Yep. Thats the tool. Saw that video few times and still do not have courage to try on my own. Intried to mirror angle and movement but not the speed and force.


Can you get a panel from a breakers and practise opn that?


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## Sicskate (Oct 3, 2012)

I wouldn't polish it up yet, it will look rubbish. 

I don't really like to give advice as it's really hard to evaluate a chip from a picture. 

Also different people have different ability's. 

I guess at this point I'd suggest making sure the chip is flat, without any low spots. 

When you use the blade, slide it over smoothly without any pressure. If it catches the chip, good. If not just keep going. 

A single chip can still take me 20-30 slides to get smooth. 

I can get you a few more pictures of different situations tomorrow if you like??


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## jure5gtt (Jun 14, 2017)

slim_boy_fat said:


> Can you get a panel from a breakers and practise opn that?


Yeah. That won't be a problem. I have spare bonnet in my shed since I'm around cars my whole life. That is good advice since last time when I was overconfident in my abilities managed to strikethrough clear with wet sanding.



Sicskate said:


> I wouldn't polish it up yet, it will look rubbish.
> 
> I don't really like to give advice as it's really hard to evaluate a chip from a picture.
> 
> ...


I thought to polish it just to see how well I can shine up blurred surrounding area and double check severity of potential collateral damage on clear coat.

Please be so kind to post up few more pics and any additional advice that crosses your mind. :thumb:

I have put on my girl panties this evening on and acted like a man...
Tried to make few more light passes over the chip and stopped there. Area (by eye) seemed to be flattened so continued with light wet sanding (just few passes) with P3000, used 3M FC Plus and afterwards 3M Super Fine. Everything looks pretty much good now. Not perfect. Still can feel under fingertip a bit raised part and from some viewing angles slight cutting mark caused by denibber. I think it is safe to try to shave a little bit more tomorrow and shine it up again. Pics to follow..

Thanks everyone for helping me out.


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## jure5gtt (Jun 14, 2017)

Tried to take a photo of repaired area but couldn't get right angle of camera to catch (probably) final result. I assume it is good result for the first timer when camera cannot catch imperfections. :lol:

Made a video.

Please notice skewed reflection on car's front bumper which is caused by slight vertical flat spot (pit) caused by denibber.


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## jure5gtt (Jun 14, 2017)

Made few more passes with well soaked P3000. You will notice (attached pic) brighter vertical line in the middle of the sanded area. That is the pit that I caused with the denibber. 
I did not go further with flattening the area since I noticed that orange peel effect on sanding area is becoming less noticeable than on surrounding area.

Slight pit is only visible if you are looking at the panel (driver's doors in this case) at narrow angle opposing the light source and "hunting" reflection defect by minimum head left-right movement.

Good news is that touch-uped spot is basically invisible from all angles and color match and blending is perfect.

During the weekend I'm gonna try to solve few more chips but on the bonnet this time. I assume that it will be much easier to "drive" denibber over the surface when you can simply place it on the surface and leave the gravity do it's part.


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## jure5gtt (Jun 14, 2017)

Made some good progress during the weekend.

STEP 1:
Rubbing alcohol 99% aka IPA wipe down.

STEP 2:
Sanded area with P2500

STEP 3:
Touched up chips with base and build up layers to create blob. Just base, not clear.

STEP 4:
Rubbing alcohol 70% for flattening by light soaking and gentle rubbing blob with cotton bud (can use 99% but 70% takes smaller amount off and can more precisely level blob).

STEP 5:
Sanded area with P3000

STEP 6: (yet to come)
Light layer of clear. Thinking of taping/masking area and use spray can to achieve thinner and more even layer.

STEP 7: (yet to come)
Cut the clear with denibber but after 7-10 days of curing since any sooner will probably pull all the filling out.

FOR BEGINNER LEVEL GUYS THAT DO NOT WANT TO TAKE A STRIKETHROUGH RISK AND/OR DO NOT OWN DENIBBER:

Must highlight that you can do all the procedure without pre and post sanding if you do not have required tools (polishing machine + paste) for returning shine once when finished but need to be more patient about layer curing (drying) time. Also, procedure with alcohol blob "melting" is 100% harm free to surrounding factory clear coat. 
Downside is that you still need to polish touched up area but you can do it simply with decent paste and by the hand. Touched up area will be, when polished, little more dull than surrounding factory clear but that is maximum visual effect you'll achieve since base coat can never be polished to level of the clear.


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