Transom Help Needed - 1975 Tri hull

[sramos]

Re: Transom Help Needed - 1975 Tri hull

The lower transom area below the splashwell is the area I think you are referring to. I can see how that may be a problem. What if a ran 2x4 on the inside and bolted it down through the existing mounting holes? I have a enough room to slide 2x4's into the wing areas. I can get two on each side. I can clamp the back of the splash well on top pretty easy. It is the lower area below the splash that I need to account for.

 

[Woodonglass]

Re: Transom Help Needed - 1975 Tri hull

Your other issue will be tabbing the transom to the sides and laying the full layers of mat and cloth on the transom. Check the first link in my signature below to see what needs to be done. It's gunna be difficult to do this right with the splashwell in the way.

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull

The whole spashwell is coming off. I am not even gonna mess around with this peace of mind is worth the extra time.

Thanks for the encouragement.

 

[Woodonglass]

Re: Transom Help Needed - 1975 Tri hull

Check the first link in my signature. It has plans and pics on how to install your transom and how to build some good clamps to get the job done.

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull

Thank you for sharing. What the does the abbreviation PB stand for? Peanut Butter?

How many 1/2 inch holes 6-8?

Thanks again.

 

[Woodonglass]

Re: Transom Help Needed - 1975 Tri hull

Yes, Peanut Butter, Resin, Cabosil and Chopped milled fibers. Holes, I'd say about a Dozen Equally distributed across the transom top to bottom. You'll need appox. 3 qts of PB to get the job done.

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull



Today I cut the splashwell out and most of the remaining interior glass around the transom area.

Should just cut out the remaining floor/string area and the existing tabs and start fresh or should I leave what is there and build it up. The areas are not damaged and very strong.

 

[Woodonglass]

Re: Transom Help Needed - 1975 Tri hull

I'd cut it back about another foot and call it good. That will give you ample room to do the job.

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull

Question about CSM. I was told by the guys at Tap Plastics that the CSM is not "rated" to work with Epoxy but some people do it anyway. I purchased some standard CSM and some hybrid cloth back and CSM top which has a weight rating around 19 oz. I am assuming that the weight of the hybrid is a good enough substitute for the 1708 and CSM is CSM?

 

[Woodonglass]

Re: Transom Help Needed - 1975 Tri hull

You don't use CSM with epoxy. Epoxy does not have styrene and styrene is required to break down the fibers in CSM. Thats why it's used with Poly with Styrene to aid in the structural integrity of the Poly resin. Without styrene the CSM will only act as cloth and CSM has very little structural strength in this fashion. A 17 oz Biaxial Cloth is what I'd recommend or 2 layers of 7 1/2 oz. E Glass cloth.

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull

So, your tutorial is set up to use Poly Resin and not Epoxy? I just re-read the page and it does not mention Epoxy anywhere so I must have inferred Epoxy and not Poly. I have read many times not to mix the two (epoxy and poly). I am guessing I can use the Epoxy but with a cloth based fiberglass? Or are your recommending that I stick with Poly.

Thanks again.

 

[Woodonglass]

Re: Transom Help Needed - 1975 Tri hull

It's your boat and your choice. Your boat is made from Poly and Poly would be just fine for the repairs and much cheaper. Epoxy requires longer layup times but it is stronger and a bit more water proof and does not stink like poly. It gives you more time to work to. Poly is much quicker to work with. Again totally your call. Either one will work.

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull



FYI - I decided to do the repair using Poly. When I started to add up the cost of the Epoxy and figuring I will need between 3-4 gallons it was just too expensive. I paid $450 for the whole boat

I have the transom core cut and I glued it last night with Tight Bond III. I will let it set until tomorrow morning (about 36 hours). I noticed in three areas at the edges there appears to be some gapping despite the massive amount of screws I planted.

My questions at this point is the small amount of gapping serious? I plan on going over the edges with and epoxy filler anyhow to fill in the edges of the plywood and seal the holes from the screws - will that take of this or do I have a bigger problem. I did put a lot of glue down so I pretty confident the lamination is good everywhere else. There was a slight warp to the boards to begin with and that may be the reason. I tried to apply some extra downforce with the weight as seen in pic #3.

Question: Is is ok to seal the transom core with an epoxy sealer, let it cure, sand it good and then go over it with the Poly Resin and then CSM wetted out?

 

[Woodonglass]

Re: Transom Help Needed - 1975 Tri hull

I would Not use epoxy. Gapping is not an issue. The PB fillets will take care of em. Your next step should be remove the screws. Mix up a 1/2 cup of thickened resin and fill the screw holes and ALL the voids in the edges. When it sets up in an hour, sand it smooth then mix up a quart of resin and coat the entire transom If you use a couple of 1x2 strips with nails in each end layed on some saw horses you can set the transom on the nail points and coat the first side. When it sets in 20 mins you can then flip it on the nail points and do the other side. Mix 2 or 3 cups at a time to save resin. Once it's all coated and tacky you can lay the first layer of CSM. Cut it about 2" over size. Lay it on and the tug and tear the edges and make em HAIRY Pour your resin in the middle and always roll from the middle out. This helps prevent air pockets. Don't over roll. If its Flat and clear it's done. Use the bubble roller. Don't use to much resin. Use a Cheap Chip brush on the Hairy edges and DAB at em DON'T brush. It will lay down over the edge. When it's done, Flip it and do side #2 the same way. You can then drill the 1/2" holes and you'll be ready to install it.

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull

Thanks for sticking with me.

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull

Question? Should I cut be transom core short of the hull edge at the top to allow for tabbing? The original (not do good construction) left the plywood at the top sunglasses. It was flush with the hull and no waterproofing which was a big reason for the rot.

PB mixture. I have resin, chopped milled fibers and cabosil. I see some guys use chopped strand in place of milled fibers. Is this all I need?

 

[Woodonglass]

Re: Transom Help Needed - 1975 Tri hull

Cut it so it's flush. You'll wrap the edges when you glass it on the bench before installation. PB for Glue has no Strand. You use that when you are making STructural PB. Different animal.

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull

Questions on clamping....

I see the two sets of bolts, washers and nuts for each brace. I dry fit them today and could not get a good clamp on the lower portion. Is there a clamp or procedure I am missing to pull in the lower transom core area?

 

[sramos]

Re: Transom Help Needed - 1975 Tri hull

Took a closer look...

Do you have a nut in between the 2x4's? Or is it just washers? A cotter pin - same as a locking washer?

Thanks again.

 

[jbcurt00]

Re: Transom Help Needed - 1975 Tri hull

No, a cotter pin is used as a stop, you drill a hole thru the all-thread and the cotter pin allows the washer & assembly to rotate and allow the nut to tighten....

Have you ever use a set of these:

If you built the WOG clamps per his details, you have to snug the jaws w/ the middle nuts, then slightly LOOSEN the other set (which spreads the jaws at that point) to tighten the jaws at the far end, down at the keel edge of the transom. In that wood clamp pix, notice how the square end of the jaws at the lower adjustment handle are further apart then in the middle. This pinches the tapered ends of the clamp together, tightening the clamp pressure at that end.

Does that help?