Steel framing interior?

[RDB]

I have been asked to assist on the interior layout of a 55' trawler and had a few questions about interior framing. When constructing aluminum yachts around 40', we would often frame up the interior walls, beds, and strorage areas in square tubing so that the interior joinery was much easier. Is this pretty much common practice with steel as well? Also, the heads used to be plated, faired, and painted in aluminum for the shower and whatnot. Whats is the norm for heads in steel boats? Any advice would be greatly appreciated.

Thanks

[longliner45]

dont know about the norms for heads in steel boats but when ever you combine steel and aluminum or any other metals, you magnifi electrolisis

[Thunderhead19]

From what I've read, you should be able to use exactly the same techniques. I think you can actually get away with using a mortar-grout type mix for fairing in a steel hull. I'm told that mortar and steel have the same expansion characteristics.

[longliner45]

just like bridges!

[safewalrus]

I've found that drilling holes in the ribs and screwing wood 'cleats' bedded in a bit of sticky is fine. You then fastens the lining/ceiling to the cleats! Well it works for me! Or bolts for the bigger bits!!

[RDB]

cheers. Thanks for the tips

[MikeJohns]

RDB

Generally with steel vessels the interior joinery frames etc are from L section steel rather than RHS. RHS would need to be sealed both ends.

For the Head dont plate in steel as you describe it will rot out eventually.
You can use alloy or stainless steel and bolt it to the sub framing. Provided its painted and out of the bilge there will be little trouble with galvanic corrosion at the joint, always think which metal is likely lower on the galv scale and make its lug the beefier one.... corrosion allowance . On steel vessels you should leave good ventilation and inspection access around potential wet areas and potential corrosion spots. These days the epoxy paints are so good that internal dissimilar metal joints seldom show any problem providing thay are not in water. External is a different story.