Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Thanks Jim, even though I was wearing the tyvex suit, it worked its way onto my ankles, face and arms. Yes, grinding glass is awesome and I really can't wait till I'm done.

Hey do you ever make it on any Missouri Lakes; Clearwater, Table Rock, Lake of the Ozarks?

I've been to Lake of the Ozarks (it's about a 3.5 or 4 hour drive for me) with some friends, but I'm not sure I'd venture out there in my little boat. That place gets seriously choppy with all those big boats in that narrow lake. We've only had our boat a year, and mostly we've boated on the Mississippi (below Keokuk) and at our lake in Canada.

As for the fiberglass, are you wearing a Tyvek suit with booties and a hood? Those really help... also, I taped my latex gloves to the sleeves of my Tyvek suit (and wore work gloves on top). That really helped. Anyway, you'll be done with the heavy grinding soon and then the fun part starts.

Looking forward to following your progress!

Jim

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Thanks for the pointers on the fiberglass. Yes, Lake of the Ozarks does get crazy.

Here are few shots from today.


Question, how clean of a surface do you need to fiberglass and gelcoat? These guys got crazy with the carpet glue and its been a pain to remove. I used the angle grinder with 36 grit to remove a big portion of it and followed up with 80 grit on the sander, but there is still a lot left in all the small spaces.

 

[StevenT]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

It needs to be very clean so you get good adhesion. You might try a wire brush on your grinder. We all have a tough time with glue removal. I used an oscillating tool to get the bulk of it off. Followed with 36 grit and wire brush.

 

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Anywhere I was going to fiberglass, I ground it down to clean glass. If it's going to be painted or covered with some sort of coating, I didn't worry about it so much.

Between stringers in the back, did you cut out the bilge tray or did you leave it in? I left mine in.

Jim

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Jim, I left it in. Question for you, how did you tie in, or did you, the top cap and in front of your ski locker?

 

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Do you mean the molded assembly that forms the floor and seats of the bow area? If so, I haven't done anything with it. Mine has a gap between it and the wood deck (right in front of the ski locker) so I might try to slide some CSM or 1708 under it when I glass the deck. I'm not sure if there is any value in that assembly being able to flex independently of the deck, so I wasn't sure that they should be tied together.

It's really cold here in Illinois; we got hit with that bit winter storm last week, and we have another one coming our way Monday night, so my fiberglassing has ground to to halt. :grumpy:

Jim

 

[rickryder]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Do you mean the molded assembly that forms the floor and seats of the bow area? If so, I haven't done anything with it. Mine has a gap between it and the wood deck (right in front of the ski locker) so I might try to slide some CSM or 1708 under it when I glass the deck. I'm not sure if there is any value in that assembly being able to flex independently of the deck, so I wasn't sure that they should be tied together.

It's really cold here in Illinois; we got hit with that bit winter storm last week, and we have another one coming our way Monday night, so my fiberglassing has ground to to halt. :grumpy:

Jim

I wouldn't glass them together....if you ever need to pop the cap that would make it very difficult.

 

[Friscoboater]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

I have been following in the shadows, and you are doing a great job so far. I am not sure anyone said anything about this or not... but you might want to take out that foam around transom so that you can tab right to the hull. If you leave it in you will not have a way to tab the top of the transom.

Just my 2 cents.

Great job so far.

 

[mwe-maxxowner]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Thanks Jim, even though I was wearing the tyvex suit, it worked its way onto my ankles, face and arms. Yes, grinding glass is awesome and I really can't wait till I'm done.

Hey do you ever make it on any Missouri Lakes; Clearwater, Table Rock, Lake of the Ozarks?

I happened to already have a pair of knit pants that have an elastic band at the ankle that are a couple inches too long for me. I put those on and leave the elastic at the bottom of the pant leg around the arch of my foot inside my shoe. No itchy ankles at all!

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Friscoboater, Larson originally only tabbed the very top of the transom to the hull. BTW, thanks so much for going through all the extra trouble of posting all the awesome pictures and videos. Between you and all the other great people on this forum, I would probably be looking a boat with a blown motor and taking a huge loss on this boat. Back to the transom, are you suggesting that instead of going with the original transom design to follow the contour of the fiberglass so that I could tab around the center portion? Or staying with the original design, but removing the foam so you can reach behind the plywood to tab?

I confirmed today that I can get marine fiberglass supplies locally. But, their expensive on the resin; $4 per pound and I was told it weighs 10 lbs per gallon so $10 more per gallon than US Composites. I’d love to business locally, but that’s a little steep. Another item, when I asked about milled fibers they said they use purlay (sp?). He compared it to the white foamy substance you add to potting soil. Sounds fishy to me. Can anyone educate me?

 

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

My transom is very similar; it was only tabbed in across the top and along the bottom ides where it met the hull. I took my foam out of those recessed pockets, but there really isn't much of any surface to tab to. Judging from how hard it was to get the old transom out (the non-rotted part, anyway), I'd say it was pretty solid.

Jim

 

[73Chrysler105]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

I confirmed today that I can get marine fiberglass supplies locally. But, their expensive on the resin; $4 per pound and I was told it weighs 10 lbs per gallon so $10 more per gallon than US Composites. I?d love to business locally, but that?s a little steep.

One thing, did you consider in the cost of shipping for the US Composites resin? If it is a local business talk to them and let them know you will be using 15 gallons on your project and you can get it cheaper other places. Local guys are more willing to negotiate with you on the price especially in bulk. They won't lose money on it but if they only keep a limited supply on hand they might be able to negotiate with their supplier and get you in a fresh order at the price that works for both of you. It doesn't hurt to ask.

 

[jsturvey]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Another item, when I asked about milled fibers they said they use purlay (sp?). He compared it to the white foamy substance you add to potting soil. Sounds fishy to me. Can anyone educate me?

Agreed. I've never done a restoration so I honestly can't speak from experience, but if it sounds fishy I wouldn't use it. I have seen someone make their own milled fibers by cutting up a bunch of CSM into small pieces / fibers. A little extra time, but it's a good way to use up your drop off and waste pieces.

 

[tpenfield]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

One thing, did you consider in the cost of shipping for the US Composites resin? If it is a local business talk to them and let them know you will be using 15 gallons on your project and you can get it cheaper other places. Local guys are more willing to negotiate with you on the price especially in bulk. They won't lose money on it but if they only keep a limited supply on hand they might be able to negotiate with their supplier and get you in a fresh order at the price that works for both of you. It doesn't hurt to ask.

Yes, I bought about 4 gallons of VE from US Composites and maybe a few gallons of poly from some other online places. Shipping costs generally run $10-15 per gallon. So, price to the door was $40-$45/gallon. At one point West Marine was having a 'sale' on poly gallons - $30 + tax. So, I filled up the shopping cart.

If you have an online place that is also within driving distance, then that would be the best way to go.

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Alright finally back at it. Today I'm hoping to get the new transom cut out. My original transom measured 2-1/8" thick and the hull is 1/4" thick. Therefore, I'm thinking of going with one 3/4" and two 1/2" marine ab plywood. I calculate that with waterproof wood glue, wrapped in CSM this will give me a little over 1.9". After I add in PB and the hull it looks like my overall thickness will be near 2.2". Does this seem okay for a VP? Should I change out one of the 1/2" ply's for a 3/8"?

 

[jbcurt00]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

I'd find the motor &outdrive specs and make SURE that a total transom thickness of 2 3/8" is w/ in specs, and not at the absolute min or max. If it's at either extreme, any slight variance, may make final fitment difficult.

Most of the I/O build's I've seen @iboats shoot for a total thickness of 2 1/8", but your's may be different...

As well, make sure to install the ply transom flat & perpendicular to the center line of the boat. Else your boats performance while on plane may suffer.

 

[rickryder]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

I agree with JB.... look it up to be sure your total thickness... It would be better to be a tad under the thickness and have to build it up with another layer of glass then to be too thick and have to rip it all out.....

 

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

I think rickryder makes a good point. When I did my transom, I was shooting for the lower end of the ranged that Mercruiser specifies, with the the idea that making the keyhole area thicker is easier than going the other way...

I found that two layers of 3/4" plywood, in addition to the thickness added by the hull, PB, and layers of CSM and 1708, was just about right. To be honest, I was probably as much concerned about uniformity of thickness as I was with anything. I didn't want to have to fix a keyhole area where the thickness varied widely.

I answered your specific question about my procedures over in my Larson thread.

Keep going, you're making great progress.

Jim

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Gents, I found out that 2-1/4 is the max allowed per VP. Therefore I will be going with two 3/4" ply's. Thanks for the info. My fiberglass order should be coming in on Thursday so I hope to get the new transom in this weekend if the weather cooperates. I plan to stick with the norm around iboats and use waterproof wood glue in between my ply and PB to the hull. The transom will also be wrapped in one layer of CSM. any other words of wisdom?

 

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Just remember: if you mess up, no matter how bad, you can almost always break out the grinder and do it over!

Jim