The stand pipe drain that goes through my dam is 36 inches in diameter at the top, there is a brush guard bolted on top. The brush guard is bolted on in 4 places and has 3 bolts at each of the 4 corners. The pipe is corrugated steel, water is leaking where the bolts go through. Does anyone have any suggestions on what type of material I could use to stop the water from leaking? It needs to some type of material that I can easily take off or uscrew the bolts at some later date. Silicone maybe? Is there some product I could use on the inside and outside of the pipe while it is wet?