Rot Doctor


Subject: Transom rebuild
Date: Fri, 22 Aug 2003

Dr. Rot, I am rebuilding the transom on my 89′ Skeeter. 18′5″—175 HP Merc. I have read many of the Q &A’s on your web site but I want to make sure I get this right. So here are some questions.
1) I need to laminate two layers of 3/4″ ply to make my transom, do I treat both pieces with CPES™ and then laminate or do I laminate and then treat?

In your case, I would laminate, cut and trim for installation, and then treat thoroughly with the CPES™, especially all cut edges.

2) What is the best way to laminate these two pieces? Should I use thin glass in between?

They can be laminated wood-to-wood if you wish. If you need a little more thickness, then yes, you can add glass cloth (not mat) to the lamination. It will use more L&L resin™, and it will also add a little strength.

3)What product should I use to bond the new Transom wood to the existing fiberglass of the transom?

You can use the L&L Resin™ for this if you wish, or, if you think you need something thicker that will hang better, then you can use our All Wood Epoxy Glue™. The glass surface should be scoured down and wiped clean with lacquer thinner before the resin is applied for bonding. It will need to be braced into place, or lightly clamped. Heavy clamping is not a good idea with epoxies… it tends to “starve” the joint.

4) What should I use to fill and bond the voids on the ends and along the bottom between the hull and the new wood? Probably 1/2″ plus in areas.

You can use our Fill-It™ Epoxy Filler, or you can custom-make your own mix from the L&L Resin™ and talc or sawdust or glass fibers, etc.

How loose or snug should the new wood be before attempting to proceed with epoxies?

It really doesn’t matter. If you can lightly clamp or brace the wood into position, in 24 hours it will be secured in place. If you have gaps or spaces between the wood and the glass surface that are not easily clamped closed, you can use a soft mix to fill, such as the Fill-It™ Epoxy Filler or a soft mix of the L&L Resin™ and filler.

5) When layering fiberglass on the new transom, what types of glass mat and in what order of lay-up would you recommend?

You’re working with epoxies here, and that means you have to stick with epoxies. You can’t use a standard polyester resin…it won’t bond well.

You should also NOT use fiberglass matting. Most of it has a binder in it which is specific to polyester resin and will interfere with the curing of an epoxy resin. Use plain glass cloth, and we’d recommend the 10 oz cloth. In laying this down, you will use approximately 10 fl oz of L&L Resin™ per sq yard of the 10 oz cloth put down. Apply the L&L Resin™, press or roll the cloth into the resin. The cloth will virtually disappear when it is saturated… thin areas can have a bit more resin dabbed on top,

How many layers of cloth you apply will depend on how much strength you are looking for. One layer of the 10 oz cloth will certainly seal off the wood and add some strength…additional layers will add additional strength.

6) I am also rebuilding the inner deck where my batteries and oil reservoir set, is there a cheaper epoxy or other product to use to cover the 1/2″ ply for this area? I know that you would prefer that I use your brand of materials.

Any epoxy resin will bond to any other epoxy resin. Our L&L Resin™ will not “blush” so it always presents a clean surface. Most other epoxies do blush, and this blush will have to be scrubbed/wiped off the surface before anything else can be applied. Our L&L Resin™ is also a slower-setting resin than most other, which will give you more working time.

7) Any idea how much CPES™, L&L™, etc I would possibly need? My transom is 86″ wide, 17″ deep in the middle, 10–11″ on the ends. Two layers of 3/4″ marine ply. Also a small bulkhead that is 75″ long, 5″ deep in the middle tapering to 1/2″ on the ends. The inner deck is 78″ x 24″. I need to treat and light glass both top and bottom of the inner deck. Foam under this area.

I’m going to let you do the math of this, Larry. For the CPES™, you will get about 150–175 sq ft coverage per gallon. This would include a good saturation of the cut edges.

For the L&L Resin™, as noted above and assuming you’re going to use a 10 oz fiberglass cloth or tape, you will use 10 fl oz of epoxy resin per square yard of cloth laid down.

For things like Fill-It™ Epoxy Filler or a custom-mix of the L&L Resin™ and whatever, it’s strictly a volume issue: As much as you need to fill the space.

Thank for any help, hope to get response soon. Been fooling with this thing all summer, need to get it done before it gets cold. Have some pictures but couldn’t get them to load.

Thanks again for any help.
Larry F.


Your questions are all good ones, and if you have any more feel free to come on back.