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The film
Answers to frequently asked questions – sorted by topic.
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All about sanding
Which grit, in which order, for which machine – and what the P stands for.
Coarse (P24–P80) removes material, medium (P100–P180) shapes and levels, fine (P220–P400) smooths and prepares, very fine (P500–P1000) mattes paint, and ultra-fine (P1200 and up) is the finish before polishing. The grit guide explains every step; the abrasive finder tells you the grit for your project.
Never more than double the grit number: after P80 comes P120 or P150, not P240. Otherwise the scratches from the coarse grit stay visible – even more so under paint and oil.
The P stands for the European FEPA standard: the higher the number, the finer the grain. American ratings without a P (“grit”) follow the CAMI standard – up to about P220 the numbers are practically the same, above that they are not: 400 grit is roughly P600.
Yes, if the diameter (125 or 150 mm) and the hook-and-loop fixing match. The multi-hole pattern fits any hole layout. Every product page lists under “Technical details” which machines the product is made for.
Mesh, paper or non-woven, which orbit, and when to use an interface pad.
With dust extraction on primer surfacer, body filler and primer, go for the mesh disc: dust passes straight through it everywhere, it doesn’t clog and stays sharp for longer. For heavy stock removal (P40 to P80) on wood and metal, paper cuts faster and costs less; from P800 a film disc is the better choice. Without extraction, mesh has no advantage.
Non-woven mattes, paper removes material. Non-woven adapts to any shape and sands without deep scratches – ideal for scuff sanding paint in swage lines, corners and on edges where paper would sand through. For levelling and stock removal, paper remains the choice. A fine non-woven pad is roughly equivalent to P320 to P400.
Around 5 mm is the all-rounder: enough removal for body filler and wood, fine enough for paint prep. 2.5 to 3 mm is built for finishing – keying clear coat, before polishing – and 7 mm and more for fast stock removal. If you only have one machine, take 5 mm and use an interface pad for fine work.
For paint, curves and edges, yes: the soft layer between backing pad and disc gives a little, follows contours and protects edges. On flat surfaces and for heavy stock removal you can do without.
Wet or dry, avoiding pigtails, when to change discs, dust, hook-and-loop and storage.
Dry with dust extraction up to about P600 – faster and no water on the metal. From P800 on paint, wet sanding pays off: water cools, rinses away the swarf and gives a finer scratch pattern. Use waterproof sheets or film discs for this; paper discs go soft.
Almost always from one of three causes: a skipped grit, too much pressure or a clogged disc. Choose the next grit no more than twice as fine, keep the sander flat under its own weight and change the disc as soon as it stops cutting. Guide coat shows you where scratches remain before every change.
When it cuts noticeably slower, the surface gets warm, there are shiny patches or clumps of dust on the disc, or single deep scratches appear. It lasts longer with dust extraction, light pressure and the backing pad kept flat.
Extract first, right at the machine – with a perforated backing pad and perforated or mesh discs. Whatever still rises is caught by a tight-fitting FFP2 dust mask. Oak and beech dust is classed as carcinogenic, and paint and filler dust has no place in your lungs either.
Usually it’s the backing pad, rarely the disc: its hook-and-loop wears out or gets clogged with dust. Clean clogged hook-and-loop with a soft brush or compressed air; if the hooks are flattened or discoloured, you need a new pad. To make it last: only switch the machine on once it’s on the surface and off before lifting it – an interface pad wears out instead of the backing pad.
Dry, at room temperature, flat in the original packaging – not in a damp cellar, not next to a radiator. Moisture makes paper curl; curled discs don’t sit flat and come off the hook-and-loop more easily. Lay slightly curled sheets flat under a weight for a day.
All about ordering
Payment methods, pay by invoice, volume discounts, quotes, shopping lists and reordering.
At checkout you can pay by card, PayPal, Apple Pay, Google Pay or Klarna – you’ll see whichever methods are currently enabled. Trade customers with a trade account can also pay by invoice.
As a trade customer with a trade account, yes – with 14 days payment terms. You can apply for the account under KORNDEX Business. Private customers pay with the payment methods offered at checkout.
Pack sizes are tiered: the bigger the pack, the lower the price per piece. Workshops, paint shops and businesses with regular demand get their own terms through KORNDEX Business – apply for a trade account and we’ll get back to you.
Yes. Put your cart together and choose “Request as quote” – the items are then already in your message to us. The price list is also available as a CSV file for Excel and inventory systems; if you know your item numbers, order via quick order.
Choose “Share as link” in the cart. Whoever opens the link is asked whether the items should go into their own cart – at today’s prices. The link only contains items and quantities, no personal data.
The cart remembers in this browser what you last took to checkout – for a year, without a customer account. Under “Order again” you add everything back in with one click. If you know your item numbers, order via quick order.
Shipping costs, delivery time, tracking, changing an order, unavailable items and withdrawal.
As long as the parcel hasn’t left: yes. Get in touch as quickly as possible with your order number – calling is fastest, as items in stock are usually ready to ship quickly. If the parcel is already on its way, consumers can use their right of withdrawal: 14 days from receipt, without giving reasons. Businesses have no right of withdrawal; ask us anyway – with unopened stock items we can usually find a solution.
Within Germany €4.90 per order, free shipping on orders from €49. Checkout shows the costs for other countries before you order.
Items in stock usually leave us within 1–2 working days of payment; delivery within Germany takes 3–5 working days. If an item isn’t available right away, the product page says so.
As soon as the parcel leaves our warehouse, a shipping confirmation goes out by email – usually with a tracking number and a link to the carrier’s tracking page. The same details are shown with the order in your customer account. If the email hasn’t arrived, check your spam folder; if the parcel hasn’t arrived after the stated delivery time, write to us with your order number.
The product page then says “Currently unavailable” with the link “Ask for delivery date”. Your message to us already names the item and variant; we reply with the date or suggest an alternative.
As a consumer you have a 14 days right of withdrawal from receipt – including for opened packs. The only exceptions are sealed hygiene items such as respirator masks once the seal has been removed. If goods are used beyond inspecting them, you may have to compensate for any loss in value. Details in the withdrawal policy.
Who is behind the shop and what the sample range is all about.
KORNDEX is just starting out. The range is being finalised with manufacturers and suppliers; until then, the shop shows what products, grits and sets will look like. Prices and series are not yet final.
KORNDEX is a brand of Custom-Automotive GmbH, based in Rodenbach. Orders, invoices and your contact person all go through Custom-Automotive GmbH – which is why it appears in the legal notice, the terms and conditions, and on our contact details and emails.
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