5" Indasa Rhynofibre Z Silver Zirconia Fiber Grinding Discs – P24 & P36

5" Indasa Rhynofibre Z Silver Fiberglass Grinding Discs

Indasa Rhynofibre Z Silver 1200 Series discs are aggressive 5" resin fiber grinding discs for fiberglass repair, composite fabrication and heavy material removal. They are an excellent choice for grinding cured fiberglass laminate, cutting back old tabbing, removing failed repairs, shaping rough edges and preparing damaged fiberglass for rebuilding.

The zirconia-alumina abrasive provides a fast initial cut, while the durable 0.8 mm vulcanized-fiber backing supports the disc during demanding grinding operations. Choose P24 when maximum material removal is required or P36 when you need aggressive cutting with slightly greater control.

Fiberglass and Composite Applications

• Grinding damaged fiberglass from boat hulls and decks
• Removing cracked, delaminated or resin-rich laminate
• Cutting back old fiberglass tabbing around stringers and bulkheads
• Grinding transom, stringer and deck repairs before rebuilding
• Removing failed fiberglass patches and previous repairs
• Tapering laminate edges for scarf-style fiberglass repairs
• Shaping cured fiberglass and composite panels
• Removing heavy gelcoat buildup from localized repair areas
• Grinding mold seams, flashing and rough composite edges
• Preparing fiberglass surfaces for new laminate or structural bonding

Common Marine Repair Uses

These discs are especially useful in boatyards, marine repair shops and composite fabrication facilities. Common jobs include opening damaged laminate around an impact repair, grinding back tabbing during a stringer replacement, cleaning the perimeter of a transom repair and tapering solid fiberglass before installing replacement cloth or stitched fabric.

The aggressive P24 and P36 grits are intended for the early material-removal stage. After the damaged laminate has been removed and the repair area has been properly shaped, switch to a finer abrasive before laminating, fairing, priming or refinishing as required by the repair system.

P24 Versus P36 for Fiberglass

Choose P24 for thick, stubborn laminate and maximum removal speed. Choose P36 for most general fiberglass-repair grinding where aggressive cutting and better control are both important.

Why Zirconia for Fiberglass Grinding?

Zirconia alumina is a durable abrasive designed to maintain strong cutting action during heavy-duty grinding. This makes Rhynofibre Z Silver well suited to demanding repair and fabrication work where ordinary light-duty sandpaper may wear quickly, tear or lose cutting performance.

• High initial cutting action: Quickly removes cured resin, fiberglass laminate and heavy surface buildup.
• Rapid stock removal: Reduces time spent opening and shaping damaged repair areas.
• Strong fiber backing: Supports the abrasive during edge grinding and high-pressure material removal.
• Heat-resistant grain: Maintains abrasive performance during demanding grinding work.
• High-strength resin bond: Helps minimize premature grit shedding.
• Stable disc edge: Useful for detailed grinding around corners, seams, tabbing and repair boundaries.

Can These Discs Cut Fiberglass?

These discs can aggressively cut back, grind and shape cured fiberglass laminate. They are useful for removing material and opening damaged areas, but they are not thin cutoff wheels and should not be used like a saw blade or plunge-cutting disc.

For straight through-cuts in fiberglass panels, use a tool and blade specifically rated for composite cutting. Use the Rhynofibre Z Silver disc for grinding the cut edge, tapering the laminate, removing damaged material and preparing the repair area.

Additional Metalworking Uses

Rhynofibre Z Silver can also be used for aggressive stock removal, weld grinding, burr removal and edge work on steel, stainless steel and other hard metals. This makes it useful in marine shops that perform both fiberglass repair and metal fabrication.

Tool and Backing-Pad Requirements

These are plain resin fiber discs with a 7/8" center hole. They are intended for use with a compatible 5" right-angle grinder, fiber-disc backing pad and retaining nut.

A backing pad is required. Do not mount the disc directly against the grinder flange. Confirm that the grinder, backing pad, retaining hardware and disc are properly matched and securely installed before use.

Fiberglass Grinding Tips

• Use controlled pressure and allow the abrasive to do the cutting.
• Keep the grinder moving to limit heat buildup in the laminate.
• Avoid grinding deeply into sound laminate outside the repair boundary.
• Taper the repair gradually rather than leaving a sharp vertical edge.
• Frequently inspect the area for air pockets, delamination and damaged fibers.
• Remove all grinding dust before laminating, bonding or fairing.
• Follow the resin or repair-system manufacturer’s surface-preparation requirements.

Fiberglass Dust Safety

Grinding fiberglass produces airborne glass fibers, resin dust and fine particles. Use effective dust extraction where practical and wear appropriate eye protection, gloves, protective clothing and a properly selected respirator. Work in a well-ventilated area and follow applicable workplace safety requirements.

Product Specifications

• Manufacturer: Indasa
• Product line: Rhynofibre Z Silver
• Series: 1200 Series
• Product type: Resin fiber grinding disc
• Primary use: Fiberglass and composite grinding
• Secondary use: Steel and stainless-steel grinding
• Diameter: 5 inches
• Center hole: 7/8 inch
• Available grits: P24 and P36
• Abrasive grain: Zirconia alumina
• Backing: 0.8 mm vulcanized fiber
• Bond: Modified synthetic resin
• Method: Dry grinding
• Package quantity: 25 discs per box
• P24 part number: 1200-24
• P36 part number: 1200-36

Frequently Asked Questions

Are these discs good for grinding fiberglass boat repairs?

Yes. They are suited to aggressive material removal when grinding damaged laminate, removing old repairs, cutting back tabbing and shaping fiberglass before rebuilding.

Should I use P24 or P36 on fiberglass?

Use P24 for maximum removal speed on thick laminate and heavy tabbing. Use P36 for most general fiberglass-repair grinding and for greater control when tapering or shaping a repair.

Can I use these discs to remove gelcoat?

Yes, they can remove heavy gelcoat buildup quickly. Because P24 and P36 are very aggressive, use care to avoid removing more underlying laminate than necessary.

Can these discs cut completely through a fiberglass panel?

They are designed for grinding and material removal rather than straight through-cutting. Use a composite-rated cutting tool for through-cuts, then use the grinding disc to shape and prepare the edge.

Do I need a backing pad?

Yes. Use a compatible 5" fiber-disc backing pad and retaining system designed for a 7/8" center hole.

Can these discs be used on metal?

Yes. They can also be used for weld removal, burr removal and heavy grinding on steel, stainless steel and other hard metals.

How many discs are in a box?

Each box contains 25 discs in the selected grit.

Order from Fiberglass Florida

Choose P24 or P36 above. Each selection is sold as one box of 25 discs. Fiberglass Florida ships fiberglass grinding abrasives nationwide and offers local pickup and technical product support through our Rockledge and Stuart, Florida locations.

Need help choosing a fiberglass grinding disc, backing pad or repair abrasive? Call Fiberglass Florida at 321-639-3046.