85 Crestliner 16 Rebuild

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

Well if it's a new to you boat, you might as well lift the decking too and check your floatation foam for waterlogging/saturation (and decking for rot on the bottom side).

Wet floatation foam adds hundreds of pounds to a boat and slows it down, the wet foam also has no buoyancy and won't float your boat in case of an emergency and it'll sink to the bottom.

To check your foam take a piece of 3/4" pvc pipe and cut some notches in one end and twist/push the notched end down through the foam 'til it hits bottom, Pull the pipe out and push the test plug out with a small rod check the bottom of the plug of foam for moisture/wetness.

Hint: if the bottom of your decking is wet, your foam will probably be saturated.

Hi Jig, just a thought, I have started the transom tear down and will then get into the floor and the below deck fuel tank. The floor seems solid so far and no signs of moisture. This boat has been in a garage for over five years (last reg sticker was 2008). If there was water in the foam would it dry out by now? Thanks

 

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

Ok, to build your transom, I'd recommend the following...

2 pieces of 3/4 plywood. Titebond III wood glue. (Gorilla Glue if you want but not needed) 1 1/4 " Deck screws. Cut the plywood to size and then glue and screw it together @ 4" to 6" spacing. Leave or remove the screws, your choice. Those screws will be sealed in, and will last the life of the boat. I used to say remove em but really no reason to. Seal the wood with your choice of methods. Epoxy is the BEST. Multiple coats of Marine Varnish is also very good. 3-4 coats of a good Oil Based paint will make it last many years. Most important thing is the edges. That's where water will attack first and easiest. Make sure they get sealed well. I like the old timers method for sealing wood. 1 part Boiled Linseed Oil, 1 part Mineral Spirits and 1 part Varnish or Polyurethane. Mix it all up and soak the wood with it. Wipe of the excess and let dry for 48 hours. Paint the wood and it'll be sealed for decades. Always remember to pre-drill and coat the holes and hardware with a good quality marine sealant, like 3M 4200 or 5200 and your transom will last as long as the boat.

Hi Woodonglass,

That confirms what I was thinking. So I believe I have the order of the process down but please hang in there with me while I ask a couple last questions.

1.) I know marine grade plywood but what finish on the screw or is this just general grade patio deck screws? I think that I would leave them in.

2.) any guideline on how to apply the glue or just brush it on?

3.) would you apply the boiled linseed oil mixture and then after it dries apply epoxy?

Thanks again. My head was spinning after reading all the different trains of thought on this one so you can't imagine my relief to nail this down!

Eric

 

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

So far as of tonight......... I just love spray foam, NOT. What a mess. I spent an hour just digging out 12 screws. That stuff clings to everything including my tongue when I had the bright idea to hold the flashlight with my teeth while cutting the foam. :facepalm: What Crestliner skimped on in transom width they sure made up for in foam!

I have the bench on the splash well loose and all cables ready to pull through the access holes on the side of the splash well.

I did find one area that I want to throw out for discussion. As you can see from the picture, the lower motor mounting holes are drilled right above the bottom of the brace that the transom wood sits in. I am guessing that the amount of wood left between the bottom of the drilled hole and the bottom edge of the wood is less than 1/2". I am wondering if when I make the transom board if I should make the bottom holes upside down "U" slots vs holes with a thin edge. I am planning on putting a wide alum spacer plate on the bilge side of both these holes to spread the load plus the motor mounting plate that is shown in the attached image. This should distribute the weight and torque across a wider area of the transom.

 

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

Always remember to pre-drill and coat the holes and hardware with a good quality marine sealant, like 3M 4200 or 5200 and your transom will last as long as the boat.

I have read where 3M doesn't confirm that 5200 works on metals as well as it does on other materials.. ie wood or plastic. Has anyone had success with it on aluminum? I want to seal all joints when I am done. Thanks!

 

[jigngrub]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

I have read where 3M doesn't confirm that 5200 works on metals as well as it does on other materials.. ie wood or plastic. Has anyone had success with it on aluminum? I want to seal all joints when I am done. Thanks!

3M 5200 Bonds securely to wood, fiberglass, gelcoat and primed metal.

I found that product description to help you.

 

[jbcurt00]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

The Starcraft guys are going to be extremely disappointed to learn 5200 doesn't work on aluminum. :facepalm:

It works on aluminum. That Jas fella should buy 3M stock he's used so much in his multiple aluminum rebuilds. He claims it really cuts the bitter in exceptionally strong coffee as well.

Jig's got ya covered too I see ^^^

An exterior grade (coated) deck screw, esp if you plan to leave them IN the transom ply.

Whatever glue you use to laminate the transom ply will dictate coverage:
PL w/ a notched trowel on both surfaces
TB3 smooth on both surfaces
I think Gorilla glue is only applied to 1 surface, and the other is slightly dampened w/ a sponge. Just enough to moisten the outer lam of plywood's face. NOT soaking wet enough to risk warping the plywood.

You want to make sure that you get good squeeze out on all 4 edges to ensure there are no voids (areas w/ no glue) between the 2 pieces. You can drill a few holes thru 1 of the 2 pieces of plywood to allow air to escape, making it easier to screw/clamp the 2 pieces together so there's 100% contact between them. Also allowing squeeze out up thru the hole to ensure 100% coverage.

The holes should be filled before proceeding to the sealing steps.

1st decide on a sealing schedule.

Boiled linseed sealer is 1 'system'
Varnish, urethane, polyurethane, or paint would be another
Epoxy a 3rd type

'Best': Epoxy then any 1 of the 2nd type, but only as a UV protectant. Epoxy isn't UV stable, so if any portion of the epoxy'd surface is exposed to UV it MUST be covered.

The Boiled linseed sealer is a good PENETRATING sealer, but to prolong it's useful life, you also cover w/ paint.

The varnish, urethane, polyurethane or paint can be used individually, or as long as they are compatible, you can 'seal' w/ one and then apply a finish coat of another. Similar to wood furniture. Some are painted then cleared over.

Read thru some of the tin rebuilds over in the Starcraft forum

LOTS of great tin boat building tips in there.

You can also find many of them here:
Starcraft Rebuilds and Restorations, they're all here!

Just like choosing what you'll use to glue the transom together, there are several choices of sealer/protectant you can choose to seal the new plywood transom. Some cost more money now (epoxy then paint to protect from UV) but offer lower maintenance & a longer service life. Others are less expensive now (hardware store porch paint) but require more frequent maintenance (re-painting) & overall a shorter service life, before it needs to be re-prepped & re-coated, not just touched up.

In general, you're doing more to ensure the transom (probably other areas of the build too) lasts a very long time compared to how Crestliner built it originally.

W/ this much time, effort & money invested, hopefully you'll keep the boat well covered, bow up & bilge plug out, so again it'll last longer then it did originally.

Good luck w your project

 

[73Chrysler105]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

FYI I keep hearing everyone talk about Epoxy not being UV stable. Epoxy will discolor in UV light but does not break down. So if it is left unpainted it will yellow. It does not break down and become weak though just ugly to see. If it is painted obviously it won't yellow. Epoxy like Poly resin can be colored and in that case becomes similar to Gelcoat and is UV stable in that it typically does not yellow depending on the type and amount of colorant. If you go this route it is the most expensive, but also the best option over all just make a colored topcoat of epoxy after its been sealed.

 

[jbcurt00]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

From WestSystems:

Coating function:
Paint or varnish applied over an epoxy barrier coat is intended to decorate the surface and protect the epoxy from sunlight. In so doing, the finish coating extends the life of the epoxy moisture barrier which, in turn, provides a stable base that extends the life of the finish coating. Together, the two form a protective system far more durable than either coating by itself.


Protection from sunlight is a primary consideration in the selection of a final coating. Long term UV (ultraviolet) protection of the barrier coat depends on the effectiveness with which the finish coating resists UV and retains it’s pigmentation and/or shield of UV filters on the surface of the epoxy barrier coat. A high gloss finish reflects a higher proportion of the light from the surface than a dull finish. Therefore, a white - especially a high gloss white – coating is much more durable.

And from WestSystem's epoxy pigment page:

It is important to realize, however, that while pigmented epoxy may be somewhat more UV resistant than unpigmented epoxy, pigmented epoxy should still be covered with a UV resistant coating, either clear coat or paint, to protect it from UV radiation for outdoor applications. While indoor applications reduce exposure to UV radiation, indoor lighting and windows will still allow exposure and a color shift often occurs, so it may be advisable to protect the epoxy indoors as well.

I think I'll cover all my exposed epoxy w/ a UV protectant, & I'll advise anyone that asks, and anytime I suggest using epoxy that could be exposed to UV, to do the same.

I found it interesting that WestSystem's recommends covering epoxy w/ a UV barrier indoors as well.

 

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

Thanks guys... I appreciate all the info.

I will probably go with the epoxy sealer. Since this transom is cased in the aluminum hull it won't be exposed to UV. Also, it is a PIA to get to so I want it once and done. I plan on keeping this one for a long time so I want to do it right.

I am glad that there has been positive experience with the 3M 5200. I want to put it on all seems that are joined together. I prefer that any water that goes into the splash well goes out the drain holes or is wiped out and not allowed to seep down into the bilge.

As soon as the boat is back together (and at this rate it will be spring here in WI) I will be taking it to a custom cover shop for a snap fit mooring cover. My boats always sit in the garage with a breathable storage cover or moored / travel with a snap cover.

My biggest concern at this time is making sure that the transom is stout enough and properly reinforced so the engine doesn't tilt like it did from the original fitting. I will post a pic tonight of the original transom if I get it out. Time to start drilling rivets after work!

 

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

I found it interesting that WestSystem's recommends covering epoxy w/ a UV barrier indoors as well.

Hmmmm ... something else to read!

 

[jbcurt00]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

Eboat: I was apparently posting while you were..... Please see my post above.

Good choice, IMHO, to go w/ epoxy. No matter how many coats you apply, I'd do the edges w/ every coat: 2 coats on each face = 4 on all the edges.

 

[Woodonglass]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

FYI I keep hearing everyone talk about Epoxy not being UV stable. Epoxy will discolor in UV light but does not break down. So if it is left unpainted it will yellow. It does not break down and become weak though just ugly to see.

Uhhmmm, I think you need to do a bit more research on this. Epoxy will in fact yellow, become brittle and eventually disentegrate when exposed to direct sunlight over an extended period of time. There are some specially formulated epoxies that have UV protection but I don't think any of the ones used here on the forum are of this type. Adding colorants to the mix does not make it UV stable. It takes other special additives to the mix to accomplish the UV stability.

This is just one article from my research on the subject...

The Epoxy Test - six epoxy types tested for UV damage

 

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

It is interesting reading the epoxy tests. One thing that I need to keep in mind is that the plate on my project is completely encased an should not be exposed to any light at all. It made me wonder while reading just how thick the coats of epoxy will be and add to the overall thickness of the plate. Is there a brand of epoxy that is a favorite in the transom world?

 

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

Today's progress wasn't as much as I hoped but did get the rivets out and freed the seams plus removed the bench. There is still plenty of foam to deal with! I was surprised and pleased with how easy it was to knock out one of the drain tubes now I just need to trace back the wires for the Lowrance and the speedo and I can remove the other.

So far with every hole that I am opening I am finding quite a bit of solid wood but with the warped surface I am sure I am going to find something somewhere.

With the VRO oil tank out and the bench gone it is easier to see what I am working with. I hate to say it but I am enjoying this experience so far more than I thought I would .... not sure what to think of that!

 

[fishrdan]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

Titebond III wood glue.

I used TB III laminating 3 pieces of 1/2" 5-ply for my fishing (swim) platform and it worked well.

any guideline on how to apply the glue or just brush it on?

A paint roller worked well for spreading out TB III, and getting the parts completely coated before it started to tack up. Put the glue in a paint pan, and roll out a nice heavy coat.

 

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

I used TB III laminating 3 pieces of 1/2" 5-ply for my fishing (swim) platform and it worked well.



A paint roller worked well for spreading out TB III, and getting the parts completely coated before it started to tack up. Put the glue in a paint pan, and roll out a nice heavy coat.

Thanks fishrdan, looks like paint supplies just hit my shopping list!

 

[Woodonglass]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

I spread the TBIII with a 1/4" Plastic Notched Trowel...

A lot of the guys use the 635 Medium Epoxy from USComposites. That's what I use. Get the Pumps makes for easy measuring.

 

[crankbait cowboy]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

i also used tb111 and a 1/4 inch trowel like woodonglass. worked real well . another idea that worked for me after considerable contemplating was i glued up my marine grade boards before cutting the transom ( using old as a template ) so as to only have to make one cut , and left a bit extra 1/8 inch on top edge so when i place back in boat i could use a belt sander to match the wood transom with the existing skin. then i dry fit it and drill all needed holes, took back out and drilled holes a bit bigger so i could get epoxy coated on edge of holes during that process. also i used clarkcraft 1 to 1 epoxy and put 2 coats on each side with edges getting a coat each time for a total of 4. really like the clarkcraft stuff and just used cheap brushes each time as no real way to clean them up. one coat each night took 4 nights and did not sand it till all done, then sanded with 120 grit belt sander lightly to smooth out and take care of any runs. be careful when applying to avoid runs or bumps from over applying will save some sanding issues.

 

[eboat85]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

HELP NEEDED! - - - --You guys are a wealth of info on making the transom. Now I feel like I have a plan of attack! But right now I have run into a snag that I would like some professional advice before I go farther.

I have everything loose except for a few transom bolts that I will need to get a drift from work to drive out. However, now that I can get into the bilge and see the assembly better I can see some rivet and welds that I am not sure how to attack.

The wood has a plate that goes from the back edge of the transom top over the top of the wood and then down into the splash well and goes back towards the hull. It looks like a "C" channel the extends the width of the hull. As it goes below the seam it is riveted to the splash well pan and the head of the rivet is in the bilge and the rest must be into the wood area.

Then the entire assemble is welded to supports that are welded to the hull bottom.* And of course, there is foam..... Lots of foam.:facepalm:

My thought is to grind the welds at the top of the supports and then try to lift the entire assembly out of the hull but before I make a mistake or go at it the wrong way I thought I would post to the group.

Here are some pics of the areas. As you can see the center upright weld already failed when the transom warped.

I have also made a cross section sketch of how I feel the transom is assembled. I might be wrong but I think I am pretty close.

Take a look and see what you think!
thanks,
Eric

 

[jigngrub]

Re: Warped transom - Replace or Repair?

Re: Warped transom - Replace or Repair?

On most tinnies those rivets go through the transom and the ouside skin:

From the one pic of the outside of your transom that you posted I can't tell if yours do or not.

All you can do is just keep taking stuff apart until you can get that booger out of there, it may put up a pretty good fight but I know you can whip it.