87 Starcraft Mariner floor

[mattsasso]

Hi all,
Benn lurking for a long time. I have an 87 Starcraft mariner 21" and I am replacing the floor. I have already ripped out the old one. Some of the foam is pretty saturated in the back so I will remove maybe the last 4 feet of foam from the hull and replace it.
For the floor I am using outdoor plywood coated in fiberglass resin to seal it and then the top will be painted with a nice rubberized non slip deck paint.

My question is this. I don't want to pop rivet the floor back down. I hate pop riveting wood. Is there a coated screw I could use that won't fry teh aluminum stringers I screw it to?

Help and thanks
Matt

 

[redneck joe]

welcome to the forum. How about stainless screws?

 

[mattsasso]

stainless does not react well with aluminum. especially with salt water

 

[jbcurt00]

Fiberglass resin? Please refer to it as Epoxy or Polyester resin.

I is suitable for use as you describe (epoxy)

The other isnt (Polyester) and it's a waste of time and money when use w out fiberglass cloth, 1708 or CSM of some kind.

Dont be surprised if water continues to drain out of the foam towards the bow when you remove the

last 4 feet of foam

Hundreds of tin rebuilds, mostly w wood decks rivetted to tin stringers, have been posted here.

AFAIK, none have complained about rivetting their deck down. A few, very few by percentage, screwed the deck down w stainless screws. None that I can recall that used some sort of coated or specially treated screw.

I'd suggest large flange (wide?) aluminum closed end 3/16 aluminum mandrel rivets to re-attach the deck.

The large flange rivet will have significantly more clamping surface area then a screw. Unless you use a washer to make the screew head's surface area larger. Then they'd be sticking up under foot unless countersunk, which means they arent holding the full thickness of the plywood.

 

[mattsasso]

whats my danger if i don't remove all the foam? is it just additional weight?

I started taking some of it out and its awful hard to get it out. Any suggestions on an effective way to remove it?

 

[mattsasso]

found a good way to get it out. cut lines with a hand saw then use a claw hammer to pull it out in chunks. goes fast

 

[ezmobee]

I just used deck screws on both my Starcraft restores. Had no issues with any of them pulling out. Rivets are better for pulling things together though. So if you have a section of deck that doesn't sit quite flat on a stringer have another person available to stand on it and keep it pushed down while you drop some screws in.

You do need to answer the above question about whether what you used was poly or epoxy resin cuz if it's poly you're gonna have a bad time if you don't add some glass to it.

 

[mattsasso]

No Title

so I took the members advice and it all has to come up. the foam is really saturated. my next question is what do I replace it with. I want floatation but I also want very good drainage against the hull and up against the floor. could use pink home depot foam and some good stuff to snug it here and there but what are your thoughts?

 

[BWR1953]

I used the pink foam in my Starcraft Kingfisher.

 

[GA_Boater]

Welcome, Matt.

The closed cell boards work out well. If you run them fore and aft, the boards sit on top of the ribs and provide natural drainage because the foam board is raised off the inner hull.

One thing to watch for, especially with the poured in factory foam, is blockage of the limber holes in the low section of each rib. The expanding foam expands right into the limbers and blocks them. Also all the loose junk like fish hooks, etc., tend to block the holes. It takes a lot of pressure washing to clear the limbers.

 

[mattsasso]

I used the pink foam in my Starcraft Kingfisher.

You are a madman. I see you even wrapped them in plastic. Good Idea

 

[mattsasso]

GA_Boater... That's what I was thinking. I have most of the foam out now and the amount of muck under it is astounding. I am leaving the poured foam in the bow because it is dry and will deaden the bang as i go through chop. also will make the floor a lot more sturdy there. I plan on loading up the storage space there. I bet the total weight of the foam I took out must be at least 400+lbs.
I also decided to drop in 3/4" ply as a floor. I think it will feel a lot more solid now that it won't have a tight pack of poured foam. also, it will be a lot better to screw seats and console to.

also now that the foam is out I am seeing the potential for am installed gas tank. Not sure about that yet but if one comes up on craigslist it may happen. I'll be moving the console forward about 6-10" to get the weight distributed well. I never liked pulling wheelies in a center console. LOL

 

[jbcurt00]

You are a madman. I see you even wrapped them in plastic. Good Idea

Note that BWR used fuel proof plastic, not drop cloth, visqueen or similar bags...

Even 3/4 ply needs to be doubled under seat pedestals and thru bolted not screwed.

 

[redneck joe]

So why did no one tell me i should not have used stainless when I was redoing the lonestar??

 

[BWR1953]

You are a madman. I see you even wrapped them in plastic. Good Idea

Yeahh... the ones near the stern where the fuel tank is located I wrapped with gasoline proof HDPE trash bags.

A bit paranoid on my part but I did have an incident with a different boat about 20 years ago. :lol:

 

[Watermann]

stainless does not react well with aluminum. especially with salt water

Can you give me an example of that? I've taken apart 40+ year old boats that showed no issue with SS bolts that were all over inside them. All the bolts/screws used in my boats are SS.

Aluminum is not that fragile but you can use a barrier if it makes you feel better, dip all the screws in 5200.

 

[ondarvr]

I'd stick with 1/2" ply, going up to 3/4" is of no value unless it's actually needed in some areas, and in that case just double the 1/2" in those spots. No need for the extra weight and cost in a typical floor.

 

[ezmobee]

I put 3/4" decks in both my Starcraft restores. I really like how rock solid they are.

 

[mattsasso]

Can you give me an example of that? I've taken apart 40+ year old boats that showed no issue with SS bolts that were all over inside them. All the bolts/screws used in my boats are SS.

Aluminum is not that fragile but you can use a barrier if it makes you feel better, dip all the screws in 5200.

I believe saltwater speeds things up but I have seen it on older boats where a previous user used stainless on a transom. but it cause galvanic corrosion. here is a link to an article. http://www.ssina.com/corrosion/galvanic.html

 

[Watermann]

Yeah leaking soggy transoms are what ruins all boats and corrodes aluminum. Wet wood is the worst and causes very destructive pitting. It's not the SS hardware used that causes corrosion, it's the lack of sealing the through transom bolts. If I was to worry about something it would be wet wood laying on bare AL not SS fasteners.

You were talking about using screws to attach the decking and if your boat has as much water contact on the decking as does the transom then there's something going on that's not good. Large flange blind rivets are a much better way of attaching your deck to thin .090 aluminum where a screw will hold only by a couple teeth and will loosen.