---
title: Metal Spray (Thermal Spray) Rebuilding | Wolf Machine Reno
url: https://wolfmachinenv.com/services/metal-spray/
business: Wolf Machine & Fabrication, Inc.
address: 4812 Longley Ln, Reno, NV 89502
phone: (775) 359-5570
hours: Shop Monday-Friday 7:00 am-3:30 pm; closed Saturday and Sunday
type: Metal and plastic fabrication and machining (custom and CNC machining, welding, metal and plastic fabrication, gearbox and part repair, align boring, metal spray)
---

[Photo: Stock photo: a lathe rough-turning a steel shaft]

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- Metal spray

# Metal spray: rebuilding worn bearing and seal surfaces

Metal spray adds metal to a worn surface by spraying it on, and the part is then machined back to its original size. We use it for bearing and seal areas, journals, brake piston seal areas, trunnion diameters and yoke seal diameters.

Line drawing.

Stock photo: a lathe rough-turning a steel shaft

Metal spraying is one of our specialties, and it shows up inside many of our part repairs. The idea is simple: a worn shaft is a shaft that is too small. Spray it back to oversize, turn or grind it to the right diameter, and the bearing or seal fits as it did when new.

## At a glance

- Rebuilds worn journals and seal areas
- Used on brake piston seal areas, trunnion diameters and yoke seal diameters
- Part is machined back to size after spraying
- A spray gun adds metal with far less heat than weld build-up

I have used Wolf Machine several times over the past few years for fabricating and repair of parts on my ultralight aircraft. [...] These guys are great to deal with. I wouldn't take my projects anywhere else.

James B. · Google review, September 2023 [Leave us a Google review](https://search.google.com/local/writereview?placeid=ChIJVWVOfCI_mYARibcFMPsDEKc)

## How the process goes

Spraying is a sequence, and the machining matters as much as the spray. The surface is cleaned and roughened so the sprayed metal grips it. Molten or semi-molten metal is then sprayed on in layers to a thickness over the finished size. The part goes back on the lathe, where the coating is turned to the original diameter.

- Clean the part and cut the worn surface true.
- Roughen the surface so the coating bonds.
- Spray the metal on until the surface is over size.
- Machine the coating back to the original diameter.

## What it suits

Metal spray is a wear-surface repair. It is the right tool for bearing seats, seal diameters and journals, where the job is to put the right size back under a bearing or a seal. Parts that need strength across the joint itself are better served by weld or a sleeve, and the full comparison is in the guide on [metal spray, sleeve or weld](https://wolfmachinenv.com/guides/metal-spray-sleeve-or-weld/).

The question people ask most is covered on its own page: [is metal spray as strong as new metal?](https://wolfmachinenv.com/faq/is-metal-spray-as-strong-as-new-metal/)

## Why shops spray instead of weld

Spraying puts little heat into the part. A long, slender shaft or a thin-walled piston is less likely to distort than it would from weld build-up around the full circumference. That is the reason it suits pistons, seal diameters and long shafts, such as [pump and turbine shafts](https://wolfmachinenv.com/services/pump-and-turbine-repair/) and [motor shafts](https://wolfmachinenv.com/services/electric-motor-shaft-and-endbell-repair/).

## What spray gives a rebuilt part

The finished result is a surface at the original diameter, smooth and round, that takes the original bearing or seal. Because the coating is machined after spraying, the size on the print is the size you get back. If you have a drawing, send it. If you only have the worn part and the mating bearing or seal, that is enough to work from.

## What to send

Photos of the worn area, the part name, the machine it came from and the diameter you need back. The old bearing or seal helps too. Attach everything to the quote request or call [(775) 359-5570](tel:(775)%20359-5570).

### Sources

- [Wolf Machine & Fabrication services list](https://wolfmachinenv.com/services/) (2026-10-18)
- [Thermal spraying (Wikipedia)](https://en.wikipedia.org/wiki/Thermal_spraying) (2026-10-18)

### Surfaces metal spray suits

- Bearing seats on shafts and axles
- Seal areas where a lip seal has cut a groove
- Brake piston seal areas
- Pinion and trunnion bearing diameters
- Yoke seal diameters

### Typical parts

- Shaft journals
- Pistons and seal areas
- Trunnion diameters
- Yokes

### Materials

[Steels and steel alloys](https://wolfmachinenv.com/materials/steel-and-steel-alloys/) [Stainless steel](https://wolfmachinenv.com/materials/stainless-steel/)

[All materials we machine](https://wolfmachinenv.com/materials/)

### How to send us the job

Drawings, CAD files, sketches and photos all help. Put a ruler or tape in your photos, show the worn or broken area up close, and note any part number stamped on it.

[Request a quote](#quote)

[What to put on a drawing](https://wolfmachinenv.com/guides/what-to-put-on-a-drawing/)

### Talk to the shop

[(775) 359-5570](tel:(775)%20359-5570)

| Monday to Friday | 7:00 am - 3:30 pm |
|---|---|
| Saturday and Sunday | Closed |

[Request a quote](#quote)

### Related

- [Metal spray, sleeve or weld: rebuilding a worn surface](https://wolfmachinenv.com/guides/metal-spray-sleeve-or-weld/)
- [Is metal spray as strong as new metal?](https://wolfmachinenv.com/faq/is-metal-spray-as-strong-as-new-metal/)

### Questions about this service

- [Is metal spray as strong as new metal?](https://wolfmachinenv.com/faq/is-metal-spray-as-strong-as-new-metal/)

## Work from the shop

[Photo: A grinder assembly: machined cutter housing between thick plate end flanges, coupled to an electric motor on a fabricated base]

Job 02 A grinder assembly: machined cutter housing between thick plate end flanges, coupled to an electric motor on a fabricated base.

[Photo: An inline grinder unit: bolted cutter housing with threaded ports, coupled to its electric motor on a steel base]

Job 03 An inline grinder unit: bolted cutter housing with threaded ports, coupled to its electric motor on a steel base.

[Photo: An industrial gearbox housing (speed reducer)]

Job 11 An industrial gearbox housing (speed reducer).

[See all our work](https://wolfmachinenv.com/gallery/)

## How a worn diameter is rebuilt

- 01 Worn The bearing or seal diameter has worn under size.
- 02 Built up Metal spray or a sleeve adds new material over the worn area.
- 03 Machined to size Then it is machined back to the original diameter.

Bearing and seal areas: metal spray or sleeve repair, on shafts, housings and pistons.

## Related services

- [Gearbox repair and rebuilding](https://wolfmachinenv.com/services/gearbox-repair/)
- [Hydraulic cylinder repair](https://wolfmachinenv.com/services/hydraulic-cylinder-repair/)
- [Pump, shaft and turbine repair](https://wolfmachinenv.com/services/pump-and-turbine-repair/)
- [Electric motor shaft and endbell repair](https://wolfmachinenv.com/services/electric-motor-shaft-and-endbell-repair/)
- [Rotary valve and airlock rebuilding](https://wolfmachinenv.com/services/rotary-valve-and-airlock-rebuilding/)
- [Rock crusher and screen parts repair](https://wolfmachinenv.com/services/crusher-and-screen-parts-repair/)

## Metal spray questions

Still have a question? Call [(775) 359-5570](tel:(775)%20359-5570), Monday to Friday, 7:00 am to 3:30 pm.

### Can you spray a part that has already been welded?

Often yes. Tell us what was done to the surface and send photos, and we will say how we would prepare it.

### What happens after the spray goes on?

The sprayed surface is machined back to the original size, so you receive a finished diameter ready for the bearing or seal.

[Photo: Stock photo: a lathe turning a bar, hot chips flying]

## Request a quote

Tell us what you need, attach a drawing or photos of the part, and we will get back to you during shop hours. Free consultations; prompt estimates.

[Call (775) 359-5570](tel:(775)%20359-5570)

- From your specifications, drawings or samples. We can also assist you in designing your product or part.
- Free consultations and prompt estimates
- Stands behind the work: Our rates are very competitive and our quality is second-to-none. Wolf Machine stands behind the work we perform.
- Company accounts: all major credit cards, or we can open an account for your company

Shop hours Monday to Friday, 7:00 am to 3:30 pm. Send your request any time and we will get back to you during shop hours.

Stock photo: a lathe turning a bar, hot chips flying