The time has come after many years to stand my mast with new chain plates ( no smart replies bob , I still have a few tins of cat food left ??) the new chain plates will be external as the existing ones are glassed into the inside of the hull , leaving me terrified of crevice corrosion, that are only 40 years old. I plan on using the existing ones as a backing plate and bolt new ones one the outside ( early manitou 32 had this arrangement ) I do not want to bend the new plates to the shape of the hull , so I will need to fill the gap , if there is any with a suitable filling compound. Most likely looking at a maximum of 6 mm at the base , the hull is pretty flat at deck level. Any ideas ? Was thinking of thickened epoxy but will it withstand compression loads. Thanks in advance
Select to expand quoteoldboyracer said..
The time has come after many years to stand my mast with new chain plates ( no smart replies bob , I still have a few tins of cat food left ??) the new chain plates will be external as the existing ones are glassed into the inside of the hull , leaving me terrified of crevice corrosion, that are only 40 years old. I plan on using the existing ones as a backing plate and bolt new ones one the outside ( early manitou 32 had this arrangement ) I do not want to bend the new plates to the shape of the hull , so I will need to fill the gap , if there is any with a suitable filling compound. Most likely looking at a maximum of 6 mm at the base , the hull is pretty flat at deck level. Any ideas ? Was thinking of thickened epoxy but will it withstand compression loads. Thanks in advance
Moi, smart replies, neeever. 
Oldboy, I've recently been playing with stainless steel and the drilling of it presents more of a challenge than bending it. Back to your question, milled fibre( glass powder) gives very good compression strength
You may need to place some sort of stainless steel compression spacer in the gap to take crushing pressure off the filler .You could weld it to the chain plate , pin it or put a bolt through it.
Agree good idea to place a shaped 316 ss compression spacer in the gap. Get flatbar and grind it to shape. Not a 5 minute job but if you don't want to bend the new chainplate flatbars this is probably the best alternative. Why don't you want to control bend the new flatbar chainplates?
Not a big cold bending job with 6mm only needed over their total length but it needs to be done professionally by a suitable shop with a cold roll set-up on the total flatbar length before you cut it to length for all the chainplates. Albeit if the bend needs to be more to the lower portion of the chainplates and flatter on the upper end this will need each chainplate cut and then bent individually to the correct shape. What is their total length? How many each side? The result will look a lot neater than adding a 6mm spacer at the lower edge which could stand out like dogs. Is the hull structure ok to withstand this new design geometry - assume so but suggest check.
If you do go the spacer route would not weld such a spacer to the 316 ss chainplate flat bar though, rather secure it with at least the lower two of the chainplate bolts as Jolene mentioned. Adhere/seal with 3M 5200. How many bolts are in each chainplate?
sscentral as here will supply all you need. Suggest Bumax 88 bolts for the new chainplate bolts - loaded in shear with all load through the unthreaded shank of the bolts so bolt head on outside. I have nothing to do with sscentral.
www.stainlesscentral.com.au/
