Problem

Cause

Solution

Deposit peels off

Poor preparation of the surface (oxidized or dirty surface).

Required surface roughness is >Ra 5.

Too low preheating temperature.

Too high preheating temperature.

Too high content of S & Ti in the cast iron base.

Clean the surface well.

Sand blast well.

Preferable >Ra10.

Increase preheat.

Decrease preheat.

Cracks

1. Overheating.

2. Too fast cooling.

3. Hardened base material.

Slower cooling / controlled cooling.

Porosity

1. Poor preparation of the surface.

2. Incorrect spray parameters.

3. Poor sealing in the torch.

4. Incorrect particle distribution for the torch.

5. Incorrect work method with the weld pool.

6. Cast iron base contains inclusions.

Clean the surface well.

Sand blast well.

Adjust parameters.

Replace seals.