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PRODUCT DESCRIPTION

DSPIAE | AS-25CPBK

Convex Sanding Board — Black

The one shape that will actually reach the inside of a curve

⚠️ No sandpaper is included, and it does nothing without it

This is a holder. It is a shaped aluminium backing that self-adhesive sandpaper sticks onto. On its own it will not sand anything, and that catches people out often enough that buyers regularly say so in reviews.

It takes 25 × 75 mm die-cut self-adhesive pads — the ones designed for this size of board. DSPIAE's own recommendations are the MSP die-cut range (#180–#2500), the SP-S01 coarse set (#180–#800) and the SP-S02 fine set (#1000–#2500). If you are not already stocked up, order paper at the same time or this will sit in a drawer.

📌 The problem this solves

There is a seam running through a hollow. The inside of an air intake, a cockpit tub, a wheel arch, the dished face of a shield or a piece of curved skirt armour. You go at it with a flat sanding stick and after five minutes the seam is still there — but the two edges either side of the dip have gone shiny and slightly flat.

That is not you doing it wrong. A flat abrasive laid across a concave surface only touches at two points, one on each side of the hollow. The middle — where the seam is — never gets touched at all, and the more you work at it the flatter those two edges get and the deeper the dip becomes. It is a genuinely unsolvable problem with a flat tool, and everyone has spent an evening on it before working that out.

🔧 Convex, not just "curved" — and why the distinction matters

Most shops call this the "curved" board, which does not tell you anything useful — curved which way? A face that bulges outward and a face that dishes inward do completely opposite jobs. DSPIAE's own shop calls it what it is: convex. The working face bulges out.

▪ A convex face sands a concave surface. That is the whole thing. The bulge sits down into the hollow and makes contact along the middle, which is exactly where a flat board never touches. Nothing else in this range can do that.

▪ It is not for the outside of a curve. Convex against convex only touches at one point. For the outside of a rounded part, a flat board rolled across the surface already works well, and that is what you should use.

▪ Forged aluminium alloy, oxidised and sandblasted. Metal rather than plastic, so the profile stays exactly as ground — a plastic block flexes under pressure and stops being the shape you bought. The sandblasted finish gives the adhesive backing something to key into, and the oxidation treatment is what stops a bare alloy block marking your hands and your work.

▪ Light, but you can lean on it. That combination is the point of aluminium. Owners describe it as light and easy to hold while still taking real pressure when a stubborn seam needs it — something a foam-backed abrasive cannot give you.

🤔 Reading the code — you are choosing a shape, not a colour

There are nine of these and the code is in two halves. The letters before the colour tell you the shape, and that is the part that matters — the red, black and grey versions of any given shape are identical tools.

AS-25FP…	Flat. Ultra-thin bevelled edge, no dead corners. Flat panels and general work — the one to own first
AS-25PP…	Perpendicular. 90° internal angle, for sanding right into a square internal corner
AS-25CP…	Convex. This one. For concave surfaces — the inside of a curve
…RD / BK / GR	Red, black or grey. Cosmetic only — this one is black

Straight answer: if you do not own any of these yet, buy the flat one first. It handles the great majority of sanding and it is the general-purpose tool of the three. This convex board is a specialist — superb at the one job nothing else does, and poor on a flat panel, where it only touches along a line. Come to it when you have met the hollow that beat your flat stick. And if the problem is a square internal corner rather than a curve, the perpendicular board is the one you want.

One thing we cannot tell you: DSPIAE do not publish the radius of the convex face. If the hollow you are trying to sand is very tightly curved, this fixed profile may not sit down into it. If that is your situation, tell us the rough radius and we will measure one before you order — or look at the AT-CSS, which has an adjustable curvature and takes user-cut strips instead.

📦 What's in the box

✔ 1 × DSPIAE AS-25CPBK convex sanding board, black

✘ No sandpaper. This is the holder only

✘ No other shapes from the range — flat and perpendicular are separate products

✘ No case or storage

📏 Specifications

Model	AS-25CPBK
Manufacturer's product name	Convex Sanding Block ("Cerberus" AS-25 series)
Profile	Convex — for concave surfaces
Colour	Black
Material	Forged aluminium alloy
Surface treatment	Oxidation treated and sandblasted
Length	Approx. 100 mm
Takes	25 × 75 mm die-cut self-adhesive sandpaper — sold separately
Compatible paper ranges	DSPIAE MSP (#180–#2500), SP-S01 (#180–#800), SP-S02 (#1000–#2500)
Range	Nine SKUs — three profiles × three colours
Country of manufacture	China

DSPIAE publish no radius for the convex face, no net weight and no barcode that we could find, so none of those appear above rather than being estimated. Worth noting too: at least one large marketplace listing describes this board as plastic. It is not — it is forged aluminium alloy, and it feels like it.

💡 Getting the most out of it

Press the pad down properly, from the centre out. Self-adhesive paper laid onto a curved face wants to lift at the edges. Start in the middle of the curve and work outwards, and it will stay put.

Match the stroke to the curve. Work along the length of the hollow rather than across it. Sanding across a concave surface with a convex tool concentrates everything at one contact point and digs a groove.

Let the shape do the work. The whole benefit is that the tool holds its profile, so light even strokes reproduce that profile on the part. Leaning on it just makes the contact patch wider and less accurate.

Change grits without changing tools. Peel the pad, stick the next one on. Working up through the grits on the same board means the geometry stays identical from #400 to #2000, which is exactly what you want in a curve.

Brush the pad out when it clogs. Plastic dust fills adhesive paper quickly and a clogged sheet burnishes rather than cuts. Thirty seconds with a stiff brush roughly doubles how long each pad lasts.

⚖️ Honest limitations

No sandpaper included. Stated at the top and repeated here because it is the single most common complaint about this product across every retailer selling it.

It is a specialist, not a first sanding board. On a flat panel it only contacts along a line and is genuinely worse than a flat board. If you own none of these, buy the flat one.

The radius is fixed and unpublished. If your hollow is more tightly curved than the board, it will not sit into it — and DSPIAE give no figure to check against. The AT-CSS has an adjustable curvature if that is what you need.

Only 25 × 75 mm die-cut adhesive pads fit properly. Cutting your own from a sheet is possible but fiddly on a curved face, and ordinary sandpaper without adhesive backing will not stay on at all.

The colour makes no difference whatsoever. Red, black and grey are the same tool. Do not pay a premium for one over another, and do not assume a colour change means a spec change.

It is a hand sanding block for model plastic. Not for metal, not for heavy stock removal, and not a substitute for a proper file when you need to take material off.

DSPIAE publish no barcode, weight or full dimensions for this item, which is why those rows are missing rather than filled with estimates.

🚚 Dispatch & delivery

✅ Same-day dispatch on orders placed before 3 PM, Monday to Friday

✅ Sent by Royal Mail 24 Tracked from our unit in Derby — full tracking from our door to yours, no import charges and no customs delays

✅ Packed properly. Tools travel in protective packaging, not a bare envelope

✅ Tell us what you are trying to sand and roughly how tight the curve is, and we will tell you whether this profile will sit in it — and which sandpaper grits to order alongside so it works the day it arrives

Hobby Heaven

By Hobbyists. For Hobbyists.

A family-run UK model and miniature supplier. We use the tools we sell, and we will tell you when something is not right for the job you have described.

DSPIAE | AS-25CPBK Convex Sanding Board — Black The one shape that will actually reach the inside of a curve ⚠️ No sandpaper is included, and it does nothing without it This is a holder. It is a shaped aluminium backing that self-adhesive sandpaper sticks onto. On its own it will not sand anything, and that catches people out often enough that buyers regularly say so in reviews. It takes 25 × 75 mm die-cut self-adhesive pads — the ones designed for this size of board. DSPIAE's own recommendations are the MSP die-cut range (#180–#2500), the SP-S01 coarse set (#180–#800) and the SP-S02 fine set (#1000–#2500). If you are not already stocked up, order paper at the same time or this will sit in a drawer. 📌 The problem this solves There is a seam running through a hollow. The inside of an air intake, a cockpit tub, a wheel arch, the dished face of a shield or a piece of curved skirt armour. You go at it with a flat sanding stick and after five minutes the seam is still there — but the two edges either side of the dip have gone shiny and slightly flat. That is not you doing it wrong. A flat abrasive laid across a concave surface only touches at two points, one on each side of the hollow. The middle — where the seam is — never gets touched at all, and the more you work at it the flatter those two edges get and the deeper the dip becomes. It is a genuinely unsolvable problem with a flat tool, and everyone has spent an evening on it before working that out. 🔧 Convex, not just "curved" — and why the distinction matters Most shops call this the "curved" board, which does not tell you anything useful — curved which way? A face that bulges outward and a face that dishes inward do completely opposite jobs. DSPIAE's own shop calls it what it is: convex. The working face bulges out. ▪ A convex face sands a concave surface. That is the whole thing. The bulge sits down into the hollow and makes contact along the middle, which is exactly where a flat board never touches. Nothing else in this range can do that. ▪ It is not for the outside of a curve. Convex against convex only touches at one point. For the outside of a rounded part, a flat board rolled across the surface already works well, and that is what you should use. ▪ Forged aluminium alloy, oxidised and sandblasted. Metal rather than plastic, so the profile stays exactly as ground — a plastic block flexes under pressure and stops being the shape you bought. The sandblasted finish gives the adhesive backing something to key into, and the oxidation treatment is what stops a bare alloy block marking your hands and your work. ▪ Light, but you can lean on it. That combination is the point of aluminium. Owners describe it as light and easy to hold while still taking real pressure when a stubborn seam needs it — something a foam-backed abrasive cannot give you. 🤔 Reading the code — you are choosing a shape, not a colour There are nine of these and the code is in two halves. The letters before the colour tell you the shape, and that is the part that matters — the red, black and grey versions of any given shape are identical tools. AS-25FP…Flat. Ultra-thin bevelled edge, no dead corners. Flat panels and general work — the one to own first AS-25PP…Perpendicular. 90° internal angle, for sanding right into a square internal corner AS-25CP…Convex. This one. For concave surfaces — the inside of a curve …RD / BK / GRRed, black or grey. Cosmetic only — this one is black Straight answer: if you do not own any of these yet, buy the flat one first. It handles the great majority of sanding and it is the general-purpose tool of the three. This convex board is a specialist — superb at the one job nothing else does, and poor on a flat panel, where it only touches along a line. Come to it when you have met the hollow that beat your flat stick. And if the problem is a square internal corner rather than a curve, the perpendicular board is the one you want. One thing we cannot tell you: DSPIAE do not publish the radius of the convex face. If the hollow you are trying to sand is very tightly curved, this fixed profile may not sit down into it. If that is your situation, tell us the rough radius and we will measure one before you order — or look at the AT-CSS, which has an adjustable curvature and takes user-cut strips instead. 📦 What's in the box ✔ 1 × DSPIAE AS-25CPBK convex sanding board, black ✘ No sandpaper. This is the holder only ✘ No other shapes from the range — flat and perpendicular are separate products ✘ No case or storage 📏 Specifications ModelAS-25CPBK Manufacturer's product nameConvex Sanding Block ("Cerberus" AS-25 series) ProfileConvex — for concave surfaces ColourBlack MaterialForged aluminium alloy Surface treatmentOxidation treated and sandblasted LengthApprox. 100 mm Takes25 × 75 mm die-cut self-adhesive sandpaper — sold separately Compatible paper rangesDSPIAE MSP (#180–#2500), SP-S01 (#180–#800), SP-S02 (#1000–#2500) RangeNine SKUs — three profiles × three colours Country of manufactureChina DSPIAE publish no radius for the convex face, no net weight and no barcode that we could find, so none of those appear above rather than being estimated. Worth noting too: at least one large marketplace listing describes this board as plastic. It is not — it is forged aluminium alloy, and it feels like it. 💡 Getting the most out of it Press the pad down properly, from the centre out. Self-adhesive paper laid onto a curved face wants to lift at the edges. Start in the middle of the curve and work outwards, and it will stay put. Match the stroke to the curve. Work along the length of the hollow rather than across it. Sanding across a concave surface with a convex tool concentrates everything at one contact point and digs a groove. Let the shape do the work. The whole benefit is that the tool holds its profile, so light even strokes reproduce that profile on the part. Leaning on it just makes the contact patch wider and less accurate. Change grits without changing tools. Peel the pad, stick the next one on. Working up through the grits on the same board means the geometry stays identical from #400 to #2000, which is exactly what you want in a curve. Brush the pad out when it clogs. Plastic dust fills adhesive paper quickly and a clogged sheet burnishes rather than cuts. Thirty seconds with a stiff brush roughly doubles how long each pad lasts. ⚖️ Honest limitations No sandpaper included. Stated at the top and repeated here because it is the single most common complaint about this product across every retailer selling it. It is a specialist, not a first sanding board. On a flat panel it only contacts along a line and is genuinely worse than a flat board. If you own none of these, buy the flat one. The radius is fixed and unpublished. If your hollow is more tightly curved than the board, it will not sit into it — and DSPIAE give no figure to check against. The AT-CSS has an adjustable curvature if that is what you need. Only 25 × 75 mm die-cut adhesive pads fit properly. Cutting your own from a sheet is possible but fiddly on a curved face, and ordinary sandpaper without adhesive backing will not stay on at all. The colour makes no difference whatsoever. Red, black and grey are the same tool. Do not pay a premium for one over another, and do not assume a colour change means a spec change. It is a hand sanding block for model plastic. Not for metal, not for heavy stock removal, and not a substitute for a proper file when you need to take material off. DSPIAE publish no barcode, weight or full dimensions for this item, which is why those rows are missing rather than filled with estimates. 🚚 Dispatch & delivery ✅ Same-day dispatch on orders placed before 3 PM, Monday to Friday ✅ Sent by Royal Mail 24 Tracked from our unit in Derby — full tracking from our door to yours, no import charges and no customs delays ✅ Packed properly. Tools travel in protective packaging, not a bare envelope ✅ Tell us what you are trying to sand and roughly how tight the curve is, and we will tell you whether this profile will sit in it — and which sandpaper grits to order alongside so it works the day it arrives Hobby Heaven By Hobbyists. For Hobbyists. A family-run UK model and miniature supplier. We use the tools we sell, and we will tell you when something is not right for the job you have described.

Specifications

Brand Dspiae
Type Polishing File / Glass File
Number of Pieces 1
MPN AS-25CPBK
Suitable For Scale Models, Gunpla, Miniatures, Airbrushing, Acrylic/Lacquer/En
Country of Origin China
Colour Red / Black

ABOUT US

Welcome to Hobby Heaven!

We're a brand built by passionate hobbyists for hobbyists. Our mission is to support all your creative endeavors, whether you're into modeling, wargaming, crafting, or art. As enthusiasts ourselves, we understand the importance of quality supplies at affordable prices.

Our carefully curated selection of high-quality materials is designed to inspire and empower hobbyists and artists alike. We're particularly proud of our innovative, cost-effective basing system - a game-changer for modelers and wargamers looking for professional results without breaking the bank.

At Hobby Heaven, we're dedicated to providing exceptional customer service and ensuring your creative projects are a success. Our team is always ready to offer advice, share techniques, or help you find the perfect supplies for your next masterpiece.

Thank you for choosing us as your trusted partner in creativity. We're excited to be part of your hobby journey!

PAYMENT

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SHIPPING

We primarily use RM24 for shipping, and we can arrange other courier services upon request. For large international shipments, we utilize FedEx. Once your order has been dispatched, you will receive tracking information. For domestic deliveries, the estimated arrival time is usually 1-4 days.

RETURNS

Please ensure that all items are returned in their original condition. Returns are processed within 1-2 business days of receipt. Refunds are issued minus the original shipping cost. All returns are handled in accordance with eBay's policies.

At Hobby Heaven, we strive to provide our customers with the best possible online shopping experience. Our commitment to excellent customer service extends well beyond the delivery of your order.

We encourage you to reach out with any questions or concerns regarding your purchase. The most convenient way to contact us is through the eBay messaging system.

Our dedicated customer service team responds to messages within 24 hours, Monday through Friday, between 8:00 AM and 3:00 PM GMT.

Your satisfaction is our top priority. We're here to help and look forward to assisting you!

WHAT OUR CUSTOMERS ARE SAYING ABOUT US

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