A standard 1% Ni weld consumable typical of that used in the Oil industry was utilised to investigate the factors which influence the efficiency of corrosion inhibitors in preventing weld corrosion. Testing was conducted on a 5-segment weld electrode in standard brine under sweet conditions. Precorrosion times of between 2 hours to 5 days were employed to assess the affect of different levels of synergist in the inhibitor and what affect this had on corrosion inhibition. Electrochemical techniques including linear polarisation resistance, galvanic current and potential measurements were made to assess the influence of pre-corrosion time and the chemistry of the inhibitor. The results indicated that the length of pre-corrosion had a significant influence on the time required for the corrosion inhibitor to reduce corrosion. It was also concluded that the rate of inhibition could be controlled by application of the appropriate amount of synergist for a particular system.