Boat cushion question from a land lubber.

[gene]

A family member gave me an old boat seat cushion to fix. The foam has turned to black powder. The cushion was made by sewing the top panel to the boxing with welt cord. Welt cord was then sewn around the bottom of the boxing. The foam was put inside the cover, then a piece of wood, or something, was put on the bottom of the foam, inside the cover, The bottom welt cord was stapled to this board that was inside the cover.

I have no idea what this material could be. It is no longer there, or it turned to powder also.

I'm going to put new foam in the cover and just stitch the thing closed without the staples. I am just interested in knowing what that material might have been. I certainly have not seen this technique in furniture upholstery before.

The foam and whatever the board was that was stapled into is all black powder, so I didn't think that a picture would be of help.

Thank you,

Gene

[baileyuph]

old boat seat

That might be a clue, Gene.  That is, the seat might not be OEM and it had a redo along the way which moisture absorbing material was added as padding, perhaps cotton.  The black indicates rot from gathered moisture.

I have seen this in old auto seats that have experienced moisture, possibly the boat seat has a similarl history.

Anyway, you redo equation sounds fine, but lesson learned here is to use water proof fillers on anything subject to getting wet.

Any reason you don't want to staple to the wood?  Then, your way, you could take the cushion in during non use.

Have fun,

Doyle

[JuneC]

Typically boats don't have wood/starboard/anything rigid in the cushion unless it spans a gap and is meant to be sat on.  It has to support weight, hence the wood.  Don't think I'd skip the support without knowing what part of the boat it goes into. 

Now days, hard-bottomed boat cushions are usually fashioned similarly to yours then boxing/welt/top plate are sewn and stapled to the wood.  Next, the welting around the base is stapled to the wood, leaving two layers of "unfinished" vinyl on the bottom.  Then the wood bottom is covered with marine underlining, turning the raw edges under and stapling very close to the edge, right along the welt.  Marine underlining looks like a fine-weave mesh that is thin, but not transparent.  Some use regular 9x9 mesh (9 threads per inch - poly with vinyl coating). 

My preferred method of doing this is to cover the wood with underlining first, then staple on the boxing/top plate and finish with hydem to cover the staples.  But this method does away with a lower welt.  Most boats have too many curves to just accept plain welted rectangular cushions. 

As for your black dust, I'd guess old charcoal grey marine foam (turns to black powder in probably 8 to 10 years depending on moisture and sun exposure) and regular plywood (also will turn to black powder, usually with white fungus growing here and there).  Makes you sick as a dog if you have any allergies at all.

June

[gene]

Thank you both for your comments. You were correct in that it was not OEM. Someone has stapled the bottom to plywood (inside the cover) and that and the foam had turned to black powder.

I do not have allergies but I could tell from the smell and black fine powder that it could certainly wreck havoc on someone who does.

After I took the whole thing apart the vinyl is in just as bad shape as the rest of it so I can't do anything with it. They need to buy new materials.

Gene

[Mike8560]

fungus growing here and there).  Makes you sick as a dog if you have any allergies at all.

June

I repaired a flats boat backrest today that had plastic over the foam lockinh in moisture the foam and rotton wood backer was the worstive seen thick slimey greeen moldy mess :o :o :o