Removing Rust Stains
George B. asked:
I recently purchased a 34′ Pearson sailboat. Everything on deck was leaking. I have repaired all leaks and I’m now left with rust stains on the hull liner. The liner is 1/8″ teak plywood 1 1/2″ off the hull and covered with thin foam and then with what appears to be burlap wallpaper. The rust stains are on the burlap under each stanchion. How do I get these stains out without destroying the glue that holds the burlap to the foam?
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The usual way to remove rust from fabric is to use a weak acid like Oxalic or Acetic. One solution is to put table salt on the stain and then saturate the salt with lemon juice. When it’s dry, brush away the salt and then rinse the area with clean water. This is much easier to do this if the headliner panels are removable so you can lay them flat. Another method is to use an Oxalic Acid product like CLR, about 1 part to 5 to 10 parts water. Brush it on with a paint brush and give it time to work. Afterwards rinse it with clean water.
If you get an uneven look due to some parts being cleaner than others you can wash the entire area with foam made from Boat Clean Plus and water. Brush on the foam and then use a wet/dry vacuum to remove the foam. This will clean the headliner and make the appearance even.
Before you proceed, make sure that it is Burlap. It is unusual for a boat manufacturer to use this type of material. More often, the material is synthetic, acrylic, vinyl or polyester, that can be textured to look like Burlap. Burlap is a woven fabric made from jute and other vegetable fibers and is typically used for shipping bags or sacks because it is inexpensive and strong.. It is porous and will allow the cleaners and water to penetrate into the adhesive and foam. Assuming that the foam is open cell, which most are for this application, the cleaners and water will also penetrate into the teak plywood. Depending on what the adhesives and foam are made of, the cleaners and water may attack them, or not. If the teak plywood is marine grade the adhesives will be water resistant, if not then the adhesives will be water based and the moisture from cleaning may cause the plywood to separate.
There is some risk. To undertake this type of cleaning you have to be prepared for the worst, which means that everything will fall apart and you will have to replace the panels. The panels will either be attached with screws, possibly covered by trim or a hook and loop system may be used, such as Velcro. Try to clean one panel first. If you are successful, then finish the job. If not, use the panels as a template for the new ones. It’s much easier replacing the plywood rather than trying to sand off the foam and adhesive, but this can be done if you have a lot of time an patience and if the plywood is still in good shape. You can substitute the plywood backer panels with foamed PVC. This material is easier to work with, lighter, more flexible, cheaper, and water, mould and mildew resistant.
Once the new backer panels are made, cut the foam backed material about 1" oversized, spray a durable contact adhesive onto the backer and the foam and stick them together. With PVC use 2 sided tape on the back of the panel and pull the 1" material over and attach it to the tape. If you’re using plywood, you will need to spray or paint adhesive onto the back, which can be a little more messy.
If a new headliner is in your future, visit www.garysupholstery.com (no affiliation) to get some ideas of the variety of products and cost, that are suitable for your boat.
Thanks for your question,