Attachment combs are popular among groomers, almost every groomer uses them, which makes them a valuable investment. The proper use and maintenance of attachment combs help to ensure that your equipment lasts longer, and you are able to safely do your job with confidence.
It's important to understand that no blade manufacturer is going to warranty a 30 blade for use under a comb attachment. That's because the blades were designed for height, not for use with an attachment. Groomers use attachment combs as a shortcut because they don't want to spend the money on a blade of the appropriate size—which can be expensive—and a comb is much easier. They are taught this in most grooming schools that I've attended.
How an attachment comb works
A regular size clipper blade has teeth that are spaced just right to guide hair into the cutting area and feed perfectly because of its tooth space. It doesn't jam or skimp unless the coat isn't tall enough, and it stands up well enough for cutting because of the space between its teeth.
The long, narrow teeth on the sole plate helps feed the hair into the single cutting teeth on the cutter. Now let's look at a #30 blade on a comb. The teeth on the attachment comb are spread too wide which doesn't guide the coat properly and can make it bend over on its way to the cutting surface of the blade. The teeth on the #30 blade are so close together, cutting at a length of 0.5mm, you don't have enough space between those teeth for proper feeding off your coat.
Also another reason, depending how dry the coat is, it makes a difference on the feeding of hair into the #30 blade as well.
I have seen many groomers blame the blade, the sharpening, and even the comb when they can't cut a dog with a comb attachment. A #30 blade is classed as a surgical cut, and is designed to cut close to the skin where the hair follicle is closer to the skin. A #30 blade was not made to cut long, heavy hair. The truth is a blade can only do so much.
If you want to test your blade, test it on the body of your dog. If it cuts without a comb and doesn't cut with a comb, then you know it's not your blade.
6 Things that can Cause Issues with Comb Attachments.
Pushing the blade and attachment comb too hard through the coat. The blade is overloaded with hair, has nowhere to go.
Damp hair. Moisture in the coat, the blade will struggle.
Dry, thick hair. Wide spaced teeth feeding into a surgical cut, will break teeth.
A slow, unserviced clipper, not running at full capacity.
Coats with product build-up will cause issues.
With all that being said, if your 30 blade is giving you a hard time with a comb, then we would suggest using a #10 under a comb attachment because the cutting length is 1.5mm. Remember you are using a blade that was not designed to be used under a comb attachment. Using a #10 you are less likely to break teeth and require expensive blade replacement.