good source for ss backing plates?

[coopec43]

Originally Posted by Chotu

Uh, no. I bought 4 x 8 sheets from a local supplier. And by Local I mean one day to drive there, and one day to drive back.

I got a sheet of half-inch and a sheet of quarter inch.

Well they aren't actually "backing plates" but I needed a variety of wedges to mount the stanchions on to compensate for the curve of the deck and keep the stanchions vertical. I laid up the polyester/glass sheet in my "workshop"

Why wouldn't you lay up a sheet of polyester/glass to the appropriate thickness required and use that? (Saves a couple of days drive!)

I've also rummaged through the recycle bin at "Productive Plastics" and got all sorts of off-cuts which I assume would make perfect backing plates.

[team karst]

My first 4x8’ sheet of g10 was via mcmaster and truck shipping; pretty painful charge.
More recently, via ebay and in ups-able sizes.

[SparkyDorado]

Don't use Starboard for backing plates- it suffers from cold flow deformation. I've seen several instances where backing plates were made for stanchion bases. Over time, the plates compress and the hardware gets loose, facilitating the need to retighten the hardware, which in turn begins to crush the deck core.

[coopec43]

Backing Plate Materials

"In a new installation or retrofit, the choice of backing-plate material is the first step. There are four main types of backing plate materials: plywood, aluminum, stainless steel, and G10 fiberglass board".

https://www.boatus.com/expert-advice...backing-plates

[Rumrace]

G10 seems perfect for the job extended longer or wider than the average metal blank will really give you a firm grip.
And Loktite

[coopec43]

Originally Posted by SparkyDorado

Don't use Starboard for backing plates- it suffers from cold flow deformation. I've seen several instances where backing plates were made for stanchion bases. Over time, the plates compress and the hardware gets loose, facilitating the need to retighten the hardware, which in turn begins to crush the deck core.

I would never attach a stanchion (or any fitting under load) to a cored deck.


Mounting hardware on cored decks: Right and wrong ways

Mounting hardware on cored decks: Right and wrong ways | M.B. Marsh Marine Design

[cyrano138]

I'll second that request for a g10 supplier in Florida. I'm on the west coast but it would be worth a drive to get it for less than what I'm finding online.



Aluminum seems fine, too. What thickness of each do you guys recommend?

[team karst]

1/4”.

[s/v Jedi]

Originally Posted by cyrano138

I'll second that request for a g10 supplier in Florida. I'm on the west coast but it would be worth a drive to get it for less than what I'm finding online.



Aluminum seems fine, too. What thickness of each do you guys recommend?

https://www.ebay.com/itm/28379370070...IAAOSwiI1eXdjH

[cyrano138]

Originally Posted by team karst

1/4”.

1/4 for Al, got it.



What about g10 thickness?


Thanks for the advice!

[team karst]

Smaller G10 plates very handi in the bilge too. Mounting float switches, pumps, etc. Backing plates for thru hulls. Mounting a HV transmit capacitor in the ER was my last G10 mission.
It is possible to drill and tap.

[Spot]

Originally Posted by cyrano138

1/4 for Al, got it.



What about g10 thickness?


Thanks for the advice!

Originally Posted by s/v Jedi

https://www.ebay.com/itm/28379370070...IAAOSwiI1eXdjH

If 1/4" is good enough for Jedi then it's...er, um...the same as the offcuts at work!

[team karst]

I have used 10 gauge SS, 1/4” G10
Avoiding Al.
Having seen Al as back up for struts with bad erosion/pits

They do make flame retardant G10, but not normally a rqmt.

[ArmyDaveNY]

What is the backing plate for? Also, where is the boat going to sail? If it is a lower load your backing plate material options may be greater than if the load is a high load. If the temperature changes are great, you may wish to consider material that expands at a similar rate as the material the backing plate is up against. There are many materials that are usable in some circumstances but not others.

[s/v Jedi]

Originally Posted by Spot

If 1/4" is good enough for Jedi then it's...er, um...the same as the offcuts at work!

This source is cheaper for G10 than the much lower quality sheets linked by Chotu. It’s eBay… I don’t know how they are, just did a search when someone mentioned buying it on eBay.