21’ SE (commercial) partial deck replacement

[tomc585]

Aluminum Fuel tank is out and clean.
coal tar expoxy best to coat it ? This stuff

Says dont foam the tank back in? hmm, wonder why. I would think the foam helps secure it and adds floatation.

 

[MickeyB]

I’m going with west system epoxy resin for the stringer work and tabbing new decking in. Pricey stuff, but their 800 tech support has been very good for a fiberglass newbie like me !

All decking and ledger boards all cut and mocked up as of yesterday.

today - fuel tank exterior cleaning and pick up rust oleum coal tar ex this after. If weather is right I’ll coat it this week.

 

[tomc585]

Keep taking pictures!

 

[MickeyB]

pic of the stringer mock up and some ledger boards.

also fuel tank all cleaned up and ready for coal tar expoxy coating.
tank is 10 yrs old aluminum and in great shape. Once stringer is in, tank follows


weather is gonna keep me from glassing stringer in this week.

 

[MickeyB]

Fuel tank coated and ready to go back in - all new hoses, wiring and sending unit ready for install. Looks like a coffin now .....



Poor Weather for glassing delaying stringer rebuild and tank reinstall. Slooow progress.

 

[MickeyB]

As I’m preparing to put things back together I’m considering some type of additional plywood backing in area leaning post / seat is lag bolted to deck. it was only lag bolted to original decking (3/4” plywood) And this was a source of water intrusion, so at a minimum I need to do a better job with sealing penetrations. I’d like to strengthen mounting area but can’t do thru bolting (no access) - maybe some type of backing underneath will work.

Any thoughts?

 

[tomc585]

Maybe a stainless backing plate? drill and tap?

 

[MickeyB]

tomc585

Thanks. That’s a good idea. I’ll have to talk to a fabricator.

I wish I could thru bolt it but no access once decking goes down.

Also on starboard side I have a spacing conflict with the pvc tube carrying cabling to engine. This very well could interfere with a backing plate, or my initial solution - which was a similar approach using additional marine plywood in that area as backing bonded to underside of decking to give me more to bite with lag bolts.

PO used 1.5 “ lag bolts to mount leaning post and 5200 to seal. Worked for awhile but since they penetrated through 3/4 “ deck, eventually water seeped in. That and a less than ideal fuel tank replacement is why I’m replacing some deck and a stringer now.

Either way I think I have to go through the new 3/4 “ decking and that was a problem before - so I’ll need to make sure those penetrations don’t leak.

Rain here in SoCal keeping me from glassing new stringer in - all my work is done outside. Don’t believe that old song that “it never rains in Southern California “ (dating myself now ).

 

[tomc585]

You'll be reinstalling an inspection/access port above the tanks sending unit. That can be any size you want, doesnt have to be round. You could have the backing plates made to fit in through the inspection port (pre drilled and tapped) or lay them in before you deck over. Once the deck is finished you can layout the through holes for the leaning post. Over drill/epoxy/ re-drill then 4200 the plates up to the deck lining up the holes. Put down some 4200 and install the post. If theres room you could also install the bolts in the plates prior to install (tread locked or tack welded) from the bottom up as studs and use acorn nuts on top.

 

[MickeyB]

Thank you for the information!!

Yes I’ve thought of access hatches to install backing plates; however the stringer / box that fuel tank sits in would be in the way because the width of leaning post extends the mounts outside the area above fuel tank.

I considered separate hatches just for this purpose but really don’t want two extra hatches in the main walkways.

yes I definitely will be doing the over drill/ expoxy/ redrill for all penetrations into new deck regardless of how I end up reinforcing the leaning post.

 

[tomc585]

Sooo looking at the pictures would your entire leaning post foot print be on the new portion of the deck? You could attach the plates prior to the floor before its permenant installation and do a few dry fits first.

 

[MickeyB]

Yes it is all on new decking and that is exactly what I was thinking!

I initially thought of using additional marine plywood in this manner, but I’m going to look at ss backing plates.

thanks for feedback - much appreciated!

 

[tomc585]

I like the idea of a treaded metal backer 5200ed in place. It'll hold anything and should last a long time.

 

[pelagic2530]

Are you planning on replacing the foam around the tank?

If not, keep in mind that the foam helps secure the tank in place and keep it from moving. The tabs that are welded to the tank are mostly to keep it from moving with the pressure of the foam as it expands, and are unlikely to be large enough to secure the tank on their own. So you'll either need to add the foam back in, or add additional bracing to support the tank.

 

[MickeyB]

Are you planning on replacing the foam around the tank?

If not, keep in mind that the foam helps secure the tank in place and keep it from moving. The tabs that are welded to the tank are mostly to keep it from moving with the pressure of the foam as it expands, and are unlikely to be large enough to secure the tank on their own. So you'll either need to add the foam back in, or add additional bracing to support the tank.

i was not planning to foam in tank. There was no foam below or above tank and it was very tight fit in between the wooden stringers when I pulled it. The tank was installed about 7 yrs ago by PO and thats the manner it was installed back then. I used it all this tIme with no issues. It’s a snug fit. Since Ive coated it while it was out I’m even concerned about how tight it will be to reinstall.

ive also read here about the tank needing to be exposed to air, which it will under and above. Maybe this isn’t as critical now that it’s coated ......

if I were to add foam what type and where can u get it? I assume it would go underneath, no room on sides. On top ?

Also I was debating whether it’s necessary to even replace the foam I removed between stringers to do stringer reaplacement... this was the only foam under deck. Is this a different weight ( ? )Foam for this area ??? I removed the least foam necesssary.

 

[MickeyB]

Finally had the time and good weather to work on tabbing new section of stringer to hull.

hopefully tomorrow I will be able to glass in it.

fuel tank is ready to go back in as soon as this stringer is completed.

 

[tomc585]

Wondering if its feasible to glass all or part of the stringer before installing?

 

[MickeyB]

I did put one coat of expoxy on stringer before tabbing to hull.
next step is 1708 cloth to come up off hull onto stringer. I’m thinking three layers on bottom 1/2 and one over top.

I suppose I could have glassEd top 1/2 before install.......

 

[MickeyB]

Project update: stringer glassed in, coated fuel tank reinstalled with new sending unit, wiring and hoses. Extra ledger boards installed In area where large bait tank sits. I’m using ss screws and expoxy Bonding for all the support pieces, however none used on the new piece of stringer and it is solid! Pretty pleased with my first go at working with epoxy and fiberglass.

ready for replacement foam and laying new deck (Marine plywood - BS1088 standard - pricey ) and new access hatches all around. The light is at end of tunnel!

 

[MickeyB]

Progress has been slow ......
this weekend had sometime to get new marine plywood decking in place and tabbed into sidewalls. Slow but steady, good thing this is not my job