Deck Hardware Questions backing plate, etc

[jephotog]

I am mounting all my deck hardware and have a few questions about it. I have already figured out what to use.

In the pictures you can see the aft stantions in that they do not sit flush. Also the outward bolt is buried behind the wood trim and into the part of the hull. I will be using a lag bolt there. The other areas will be using bolts, backing plates and locking nuts.

How do I cut 1/8" 316 steal for backing plate, without big power tools?

The stantion on my pulpit ended up a little too wide. Unfortunately I had drilled the holes already. See Photos.

Should I epoxy over the holes and bend the pulpit in more?

Or could I grind out a little bit of the ridge in the deck and mount then mount the pulpit flat?

One last question, what are my epoxy options when it is not going to be above 50 degrees for the next 6 months?

[mitiempo]

I'd build up a flat base under the stanchion base with thickened epoxy to make it sit flush. A lot neater than grinding the deck in my opinion. You probably can't cut 1/8" ss without power tools unless you have a month to spare.
You could go to a local welder with the ss marked and for a small charge they will cut them with a plasma torch - fast and painless. West epoxy works down into the 40's and lower so no problem there.
Brian

[sailingfool]

Use alu backing plates, steel is overkill.

[Capnblu]

Look for someone local with a water jet table, or a metal fabricating shop. I bet things are pretty slow in most shops, get all your pieces together, measure everything accurately, and WRITE IT ALL DOWN, then take it all in at once, probably cheaper than you would have expected. Definitely easier if you don't have any tools yourself.

[Deadeye]

Brian and sailingfool are bang on.

Mounting the stanchions as you show will trash the gel all around that radius and will let water in eventually, regardless of how well-bedded it is. For a good fit, mix epoxy and cabosil (fibers). Tape the stanchion base with packing tape so it doesn't stick and bed it the way you would with sealant. You can add some talc or white flour as well so it'll be easier to match the paint to the gel later.

Aluminum is a WAY better for a backer in your application. 1/4" will be plenty rigid and easier to work than your 1/8" steel. If you have some other reason for using steel (like if the backer were outside), grab a 5" angle grinder (about 40 bucks) and some cutoff wheels. They make wheels specifically for stainless and they're just a few bucks each.

You can cut aluminum with a normal jigsaw. Use a wood blade so it doesn't pack up and wax it with a candle (or Alu-Cut). The chips are annoyingly hot.

[RXBOT]

Find a fab shop with a shear. Quick and easy way to cut plate of any type up to about 3/8 inch if they have strong enough shear.

[mitiempo]

Any metal shop should have some way to cut neatly nowadays, plasma, shear, etc. But I agree the aluminum is easy to work - cut with a jigsaw and wood blade easily.
Brian

[Waltthesalt]

When I put in backing plates on my stanchons and other deck fittings using 1/8" stainless and I cut it with a hacksaw with no problem. You need a fresh blade and may even need to replace it. SS is harder on the drill bits. 1/8th is overkill on the stanchion backing plates. I only used the 1/8th where I expected a lot of load. Thinner plate would easily meet the load for stanchions... think of it as a big washer. Stanchion load isn't a lot compared to cleats and things like that. I've read testing that found the stachion post is far more likely more likely to bend that a backing plate pull out. I'd be concerned about the ss/aluminium corrosion issue with aluminium as it would occur at the bolthole. More of a long term issue.

[mitiempo]

Corrosion shouldn't be a problem inside if the holes are epoxy potted properly and the bases are properly bedded. Butyl has the most elongation of any sealant so would be an excellent choice. If not sealed properly and water gets in there are problems bigger than corrosion.
Brian

[Faster]

A minigrinder with a "zip blade" cutter will cut 1/8" SS, but you'll need a box of cutters as they wear down fast... be sure and use protective eyewear and gloves.