pressure-treated stringers or not.....

[bashr52]

Well my quick weekend bilge-pump install project turned into a total re-do of the floor. All the foam above the floor was ok, anthing below it (including the floor itself) was completely soaked and rotten. (it appears a previous owner had a fish finder on at one time that was removed and the holes never filled). Once I got the floor off, it looks like when the 2 part foam was installed at the factory, some leaked over into the center chamber, which blocked all drainage flow to the plug hole on one side. The other was a partial blockage.

The center stringer was completely wrapped at the factory, so that is still good, the other two were only partially and are now missing. I want to only have to do this once, so should I go with something pressure-treated and then wrap them, or would wrapping regular wood be sufficent? I've read where pressure treated will react with aluminum, but what about fiberglass?

Also, while I have it all apart I would like to install a center floor locker. Anyone have any ideas or suggestions?

The boat is a 1980 17 foot imperial tri-hull with an 85 horse chrysler.

Here's a quick pic I shot with my cell of the current status of this project.

 

[Woodonglass]

Re: pressure-treated stringers or not.....

Welcome to iBoats! Most of the guys on iBoats have used laminated 3/4" Ext. Grade Plywood to fabricate their stringers. I supposed you could configure your stringers and cross supports to make a deck locker (boats don't have floors). You should coat the stringers with resin and glass em in. Stick em to the Hull with som PL adhesive and you should be good to go. How's the transom? Have you checked it? You might want to drill some exploratory holes in from the inside about 2" from the bottom and see if you get wet or dry shavings? If you were that wet you might have some rot in the transom as well. You can use the blue or pink slab foam at Lowe's or HD to replace your foam. Just make sure and make allowances for drainage to the bilge.

Good Luck with your project.

 

[bashr52]

Re: pressure-treated stringers or not.....

Transom seems solid from what I can tell, I'll punch some holes in it though. The whole thing was fibergalssed over pretty well, so it seems that may have protected it. Although if those holes were left open for long, it seems like water could have gotten onto the wood in that corner and started making its way through? I bought the boat form a guy who had bought it last august, test drove it at the lake before bringing it home and putting it in the river behind his house. There he was able to run it once or twice before it overheated and cooked 2 cylinders (chances are it was running hot before he bought it and setting off the alarm, so the owner simply disconnected the buzzer to make it stop. Thats how I found it under the dash). It was also given new paint and interior just before he bought it, which makes me think the owner had known it needed major work, and simply dressed it up enough to push it down the road. He then proceeded to burn out the starter trying to get it going again, and parked it.

The wood that came out from the stringers is almost identicle to 1inch decking board, so it would be easy enough to just get a couple of pressure treated decking and glue it down and glass it it. That way I wouldnt have to worry about it again, even if a little water did seep in in a few places.

Is pressure treated on fliberglass a concern?

Edit- I've seen claims that bodning fiberglass to pressure treated is nearly impossible and the strength isnt there like untreated? Is that true?

 

[Woodonglass]

Re: pressure-treated stringers or not.....

The Chemicals used in PT wood can cause problems with Fiberglass bonding. Some have used it as long as it is good and DRY!!!!!! I Personally would NOT use it. I souunds to me like the PO was into QUICK Fixes and not doing things the right way. I am into doing things the right way soooooo...... It is up to you in how you fix YOUR boat. I can only tell you what I would do. IF you are planning on keeping this boat for any length of time and don't mind spending some time, effort and money, then I would investigate what most of the guys on iBoats have done and do it up right.

I'm just sayin.....

 

[Bob_VT]

Re: pressure-treated stringers or not.....

PT really has to be dried before you try to keep resin sticking. Go with an exterior plywood from a box store where it is stored indoors It is normally drier then PT.

 

[Mark42]

Re: pressure-treated stringers or not.....

If you are using 1/2 or 3/4 ply, it will dry fast. Give it a week or so. Be usure to have it weighted or tacked to a bare stud wall so it will have both side exposed to air for even dry. Then go ahead and install it.

I use pressure treated when ever possible when making parts for my boat.

 

[bashr52]

Re: pressure-treated stringers or not.....

I'm going to head to Lowes or something tonight I think and see what they have available. I may just end up going with un-treated and making sure it has a nice even coat of glass on it.

Another thought, what about that synthetic home decking board? IT's expensive but since it is a plastic compund would never go bad...... Not sure if anything would stick to it though.

 

[ezmobee]

Re: pressure-treated stringers or not.....

Another thought, what about that synthetic home decking board? IT's expensive but since it is a plastic compund would never go bad...... Not sure if anything would stick to it though.

Less strength, more weight, and you're probably right that nothing will stick to it.

 

[Woodonglass]

Re: pressure-treated stringers or not.....

And that plastic stuff has NO structural strength. Others have mentioned it but NO ONE has recommended using it. I would stay away from it. Stay with what the majority of the users have used and been successful with. Exterior Graded plywood, resin and Glass, and PL Adhesive!!!!

 

[Yacht Dr.]

Re: pressure-treated stringers or not.....

Hello Bash..

Dont get me wrong here..but you said

"The center stringer was completely wrapped at the factory, so that is still good"

Call me silly but did you actually core sample ? Just because it was wrapped in FG does not mean its good .

As far as PT vs. ExG vs. Marine plys ?

IMHO the sanity of Knowing.. that in the future.. you did Everything possible to do the job right..with the extra cost of labor and/or materials. It will be peace of mind ..

Then again.. I dont work on my own boat..I work on other families boats. I know that every single repair is done with the best of the best in materials and workmanship.. ( Families I dont know depend on me ).

YD.

 

[bashr52]

Re: pressure-treated stringers or not.....

Disregard my previous comment. I checked the middle stringer again last night and have decided to do all three at once. I bought 4 sheets of exteripr plywood last night, 2 large sheets of foam, and 3 1x6x10ft solid pine bards last night for stringers. They are identicle to what came out. I'll be pulling the middle stringer tonight, and cutting away some of the fiberglass at the bottom of the transom to determine what kind of shape it is in and how much will need to be reaplced. It appears the transom was built in 3 different sections, so I am hoping I can get away with just replacing the affected bottom section.

Lowes did not have that pink/blue foam, but instead they had large sheets of material that looks like a styrofom cup. I figured it would work ok since you can leave water in a stryofoam cup for a long time and it never gets wet?

 

[Woodonglass]

Re: pressure-treated stringers or not.....

Doing a Partial replacement of the Transom is NOT advisable. This would jeopardize the structural strength of the entire transom. Since you are already to the point of restoring the stringers you SHOULD IMHO replace it ALL. It does NOT take that much more effort and in the long run will give you a boat that is structurally sound and will last you for decades. PICS would really help all of us to help you!!!!! Have you decided to use Poly or Epoxy resin? Have you located a source?

 

[ezmobee]

Re: pressure-treated stringers or not.....

Lowes did not have that pink/blue foam, but instead they had large sheets of material that looks like a styrofom cup. I figured it would work ok since you can leave water in a stryofoam cup for a long time and it never gets wet?

NOPE! That stuff sucks up water like a sponge (given some time). Either find the sheet foam somewhere or get yourself some pool noodles.

 

[Mark42]

Re: pressure-treated stringers or not.....

NOPE! That stuff sucks up water like a sponge (given some time). Either find the sheet foam somewhere or get yourself some pool noodles.

That and the fact it will just melt away when resin hits it makes it totally incompatable. Try the blue foam board with the foam back. That will not melt under resin, and although it offers no strength, with sufficient lamination, you will have solid fiberglass stringers that will last forever.

 

[bashr52]

Re: pressure-treated stringers or not.....

That's weird, Lowes shows that foam on their website, but I didnt see it in the store last night. I guess I'll have to check again when I take that stuff back.

There's a local paint/auto body supply warehouse nearby I can get materials at cost. I was leaning toward poly, due to the cost and that is what the boat was originaly put together with.

I havn't gotten into the transom yet to see what it looks like..... Probably bad like the rest of it, but I keep hoping I'll get lucky somewhere along the line with this project and POS boat.

How are ski lockers usually put together? Are they actual sealed containers, or just provide access to the bottom of the boat for ski storage? I was measuring last night and it looks like I could do some sort of storage compartment thats about 5 feet long if I wanted to box it in and make a complete housing.

 

[Wingedwheel]

Re: pressure-treated stringers or not.....

Most lockers are just cavities in the hull under the deck. You can add a sub-deck to the top of your middle stringer and use the outer stringers for the sides or just add your own sides to get the size you like. When you replace the deck, just cut the locker door into it and glue resinated stops with PL. They make alot of nice stainless hardware thats inexpensive for the hinges and pulls. Just make sure you use a good sealer wherever you drill holes for the hardware.

 

[bashr52]

Re: pressure-treated stringers or not.....

OK thanks. I didn't really want to just have a door that opened to the bottom of the boat and exposed the middle stringer! Not sure how deep it will end up being, but I'll run a piece of resinated plywood along the top of the middle stringer to act as the bottom. That way if there is any water that gets in, it will be below whatever is in the locker.(in case its towels, or clothes or something that we don't want wet. What size holes would be good for drainage?

I finally have some good news! I stripped the bottom 6 inches of fiberglass off the lower transom last night and found good wood! I'm going to expose a bigger section tonight to get a better look around, and let air get in to evaporate any moisture that may be there. The stringers ran tight to the transom on both sides with no provisions for drainage. This I will fix by notching the rear of my new stringers. I'm planning on running some angled braces from the transom to the two outside stringers as well for added support. There wasn't anything there before, but a little entra can't hurt!

 

[Wingedwheel]

Re: pressure-treated stringers or not.....

A couple of 1" holes in the bottom of your locked should give you decent drainage. You might want to glass the inside corners together so that if water does get in from rain or swimmers walking across the deck and dripping the water goes out the drain holes instead of just through the cracks.