Replacing deck, stringers and transom, surface prep questions

[igy]

Hi all pretty new to the forums while I have found a huge amount of info on here I still have a few questions.

I am repairing an old 15' fibreglass boat, and need to replace the stringers, transom and deck...fun fun fun.

The hull is still intact, my first question is- do I need to remove the paint (I assume its paint) from the inside walls of the hull (visible areas) when I am tabbing in the deck. eg does the new fibreglas need to contact old fibreglass or can I simply rough up the surface in prep for fibreglassing?

Also what is the PL glue you all refer to for bedding in the new stringer timbers?

Is PB available pre-made, commercially ready to go and what is a good choice.

I am sure I will have more questions as well so please be patient!!!
cheers
Ian

 

[carribbean soul]

Re: Replacing deck, stringers and transom, surface prep questions

read this thread:

http://forums.iboats.com/boat-resto...vx-18-complete-restoration-thread-585518.html

there is a you tube video on making PB, yes its commercially available at $20 per tube called six10 or make your own for a lot less $.

 

[GT1000000]

Re: Replacing deck, stringers and transom, surface prep questions

Welcome to the dry dock, igy...

The previous link is full of excellent info as well as this one...http://forums.iboats.com/boat-resto...r/how-tos-other-great-information-288451.html

Read through those and you will begin to get a good understanding of what it is all about...

You can also look to the links provided in some of the signatures of those that respond here, to read about their on-going restorations...

Good Luck and Have fun!

Oh yeah, and don't forget to post up a ton of pics of your project...

GT1M

 

[a1964rn]

Re: Replacing deck, stringers and transom, surface prep questions

Welcome to iboats.
Yes you do need to grind down to fresh fiberglass to tab in your deck, stringers, or anywhere else you lay new glass.
PL is a polyurethane underlayment glue that comes in a caulking tube. you can buy it at Lowes, Home Depot, or other places. My cost is about $7 a tube.
PB is short for Peanut Butter, which is the consistency of the thickened resin. As mentioned above, look at the videos and you'll see how to easily mix your own, however, if you're using epoxy, the process will be slightly different.

 

[73Chrysler105]

Re: Replacing deck, stringers and transom, surface prep questions

The PL as FriscoBoater Explains is labeled PL Premium at Home Depot and Lowes it is cheaper to by the 28oz tubes instead of the 10oz tubes unless your not going to use it all at once. I am using epoxy with my restoration and making my PB with sawdust and the epoxy mix about 5-10 times the amount of saw dust as the epoxy it gets real thick and hardens quite well. It truly looks like peanut butter. I got my sawdust for free from Home Depot just ask the guys at the cutting machine for what they have they just clean it out and throw it in the trash at the end of the day. If you do use Epoxy versus Poly resin make sure to give yourself enough time to let the epoxy set. I did a small project recently as a test base and made up the resin used some for PB and didn't let the PB kick start to kick before putting it on and the plain resin started to kick before the PB was ready on the part. Resin will always kick faster in large volumes versus small volumes.

 

[JASinIL2006]

Re: Replacing deck, stringers and transom, surface prep questions

I'm sure you've seen that there are lots of the threads on rebuilding stringers. A lot of guys have used PL Premium from a tube. It is convenient and easy to apply, but it requires about 72 hours to cures (so no progress on the stringers for 3 days after using PL) and it probably isn't the best thing for making fillets.

Peanut butter, made from thickened polyester resin (or epoxy) is a bit messier. If you use polyester resin (pretty common in boat building and repair), the peanut butter cures in an hour or two, and you can continue with glassing in your stringers in about that amount of time. The thickening agents for polyester resin-based peanut butter are Cabosil or Aerosil (which are brand names for fumed silica, a fine white powder) and some type of fibers, usually 1/4" chopped strand.

Check out the Friscoboater's thread. He has a video on making peanut butter with poly resin.

Good luck,
Jim

 

[igy]

Re: Replacing deck, stringers and transom, surface prep questions

Welcome to iboats.
Yes you do need to grind down to fresh fiberglass to tab in your deck, stringers, or anywhere else you lay new glass.
PL is a polyurethane underlayment glue that comes in a caulking tube. you can buy it at Lowes, Home Depot, or other places. My cost is about $7 a tube.
PB is short for Peanut Butter, which is the consistency of the thickened resin. As mentioned above, look at the videos and you'll see how to easily mix your own, however, if you're using epoxy, the process will be slightly different.

Thanks a1964rn

Grinding back to fresh glass - I knew you were going to say that although I was hoping like crazy that you wouldnt. :lol:

And thank you everyone for your comments and assistance. I am in Australia so my replies may not be instant, you know the man that allows the internet traffic to leave Australia may be on a break or something!!!

I have watched plenty of Jays videos and have read through his thread, yes great info and very helpfull.

I am in the process of restoring a mid '80s (I think) Swiftcraft Stiletto apparently a great little sports boat (Aust design). So I have the deck out, have chased the rot up the stringers and got back to good wood. The transom ply fell out like paper so dont quite know how the outboard stayed on the back!!! My 12yo son keeps appearing at the shed door "finished that boat yet dad".... so I better get a move on, as mid way through our Summer already. I will try and get some pics up soon if anyone is interested.

I am replacing the transom from the inside, although I now think I will have to take out the well etc, probably easier in the long run.

So thanks again and will get some pics up
cheers
Ian

 

[jbcurt00]

Re: Replacing deck, stringers and transom, surface prep questions

Lets drop this over here in your thread, so that the answers show up where you need them:

Hi Charles sorry I am not trying to derail your thread, and this question may help anyway. I am in the early stages of a restore myself, eg full stringer/deck/transom rebuild. I am a bit confused about something.

I have a question re PL Glue that everyone talks about. I am going to use this to bed in the stringers, laminate the ply for the transom, glue the transom to the outer fibreglass skin, fillets, etc etc. Now I know PL glue is a construction adhesive, and I have seen mentioned 3M 5200. Is this a hard drying adhesive, or is it the flexible adhesive/sealent. If its the harddrying (sandable) construction adhesive wouldnt this defeat the purpose of keeping the stringer off the fibreglass to stop 'hard spots", and wouldn't using "peanut butter" also create hard spots.

If its the flexible adhesive/sealant then can you fibreglass over this?

The reason I ask this is I am in Australia and many of the products you use are not available or repackaged/branded!

One of the products that is readily available in Oz is the Selleys range, this is what I can find thats similar:

Polyurethane Construction Adhesive at SelleysSelleys Australia

So the Selleys Pro series Adhesive/sealent retains some flexibility (although still quite firm), while the Liquid Nails Platinum is "quite a full on adhesive, sandable" quote from Selleys tech support. They also reccomended the selleys aquadhere durabond for laminating the ply for the transom.

So any advice/reccomendations would be appreciated, and hopefully Charles this may answer a question for you and some others who tune in. cheers Ian

The hard spot created by a POINT load of a stringer against the hull is prevented by bedding the stringer in PB or PL. The stringer has a small profile along it's narrow edge. The bedding creates a wider cross section that spreads any loading across a much larger cross section then 'just' the narrow plywood edge. That would be the hard spot....

Some manufacturers raise the stringer off the hull & while suspended, tab the stringer to the hull w/ fiberglass alone, no bedding......... Of all the stringers I've seen posted to Iboats, the large majority of stringers delaminated (glass or tabbing broken/torn free) from the hull were installed w/out bedding. <<<--- Not proof positive that bedding is required, but enough for me......

PL Premium dries in the middle ground somewhere between fairly flexible & fairly hard. PB dries hard, and although if you search thru my posts, I've often supported PL's use for bedding primarily for it's somewhat flexible bond, a great positive in my mind, it does have drawbacks. And you need to be aware that it off gases for 72+hrs, so further work is delayed. As it cures it bubbles when applied heavily or in thick beads (like a fillet), sometimes it bubbles a great deal.

I've not seen 3M 5200 suggested as an alternative bedding compound, but I do think it dries to a somewhat sandable surface, but it too takes quite some time to cure, maybe even longer then PL.......... May not bubble as it cures..... It's expensive... I'm not sure it would make my list of favorites for bedding......

Although fiberglass & resin once cured might have some 'give' or flexibility to it, I don't think that the Shelly's flexible PL will remain that flexible once glassed over......

Since you're working on a fiberglass boat, and will be using polyester resin & fiberglass, I'd suggest that you use PB to bed the stringers, make your fillets & to bond the transom to the fiberglass transom skin. You'll be using a bunch of poly resin & etc to make fillets and for all the glass work, and buying the materials in bulk anyway.

Just my $0.015

If you want to give the Shelly's PL a go, I'm sure the rest of the Aussie/NZ iboaters will benefit from the results you post, for good or for the bad..........

Hope some of that ^^^ helps.........

 

[igy]

Re: Replacing deck, stringers and transom, surface prep questions

Hi jbcurt00

thank you for that, you have summed it up very well for me and I am now looking at it differently. I think the clearest and helpful fact above was that " the selleys PL will not remain too flexible once encased in fibreglass". I think for me that is the gem, and I hadnt considered it that way, so thank you

today I actually bought a tube of the selleys liquid nails plat and a tube of Sikaflex 291 adhesive, so I have glued some timber and created some fillets as a trial. I will let everyone know how that goes.

once again thanks for all the assiatance