Transom thickness/one or two pieces of plywood?

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

pmshoemaker

Well-known member
Joined
Mar 31, 2017
Messages
51
Reaction score
0
It's been a year, but I really want to get back to work on my 81 Polar Kraft project. Last completed stage was removal of the old transom board. I'm now ready to start fabricating the new one, and after studying the tutorial on transom building, I was wondering, is there an advantage to sandwiching 2 pieces of plywood together to create the correct thickness? Or would it be just as effective to try to purchase a piece of ply that is already the right thickness? The actual thickness of the old transom (based on the scrap of it that hadn't rotted away) was exactly 1.25". I'm pretty sure I can find plywood that thick. Should I just get a single piece of 1.25 and seal it?
 
One piece would be stronger (maybe not a lot). Remember plywood is already multiple layers of wood glued together. But will cost you more IF you can find it. Post what you find.
 
I would use two pieces because in my neck of the woods I think I would have a tough time finding 1 1/4" exterior ply. If I could find it I'm sure it would be $$$$$. Additionally, you have nothing to lose using two thicknesses other than the cost of good adhesive. YMMV.
 
Never heard of 1 1/4" plywood. If it is to be found, I would think it would be pricey. If you sandwich 1/2" and 3/4", it would be a perfect match. Plus, you are more than likely to find partial sheets of these sizes.
 
thanks fellas -- yes -- I only know IN THEORY that 1.25" exists -- haven't started looking for it to purchase, and I'm sure it would be a bit pricey. Since I have you all here, any thoughts on using the glue vs. epoxy route? I see both methods on the transom tutorial, and while I have a sense that the epoxy glass/resin method is probably the preferred method, it seems a lot more complicated and expensive than a bucket of glue to mate the 2 boards together
 
In addition to WV's comment I would add that Titebond III is waterproof. It is not for structural bonds but would work well for laminating two pieces of ply together in this application. Epoxy is waterproof and structural, and unlike Titebond III will adhere to more than just wood. It is also more $$$.

If you use Titebond I recommend you cut the pieces slightly oversize, glue them together, then cut to final size. Reason is you will be spreading a lot of glue and will have limited time before it starts to set. Not having to worry too much about perfectly aligning the pieces, not to mention squeeze-out, just makes life a little easier.
 
Keep in mind that most people that put lots of elbow grease into a repair like this don't let it fill up with rain water again.

My point is that any reasonable repair will last a long time.

A sealer for the ply would be money well spent.
 
Awesome advice as always -- I'm leaning toward the Titebond III -- I can have my grubby little hands on that with a quick trip to Lowes, and can get this project moving again immediately! Yes, LDUBS, I'll create a blank bigger than the area needed, just like on the tutorial I found on this site. And yes, CedarRiverScooter, this boat was nothing much more than a rain barrel behind my dad's garage for a good 30 years!!
 
Pretty much all manufactures will laminate two pieces together, 1" thick and thicker ply wood is made but, not usually readily available, there is nothing wrong with gluing two pieces together, it is simply glue together veneers anyway. Most of the transoms I have seen are a minimum 1.5” thick, two pieces of 0.75” plywood laminated together.
 
Without knowing the size of your transom (or how large a blank you’re going to lay up) and whether you’ll be using sanded fir or sanded southern pine, you’ll want to give some thought to how you will ensure good contact in the center of your blank. Southern Pine is particularly prone to bowing, often the result of how the panels are stored. Clamping around the perimeter may be adequate but if your panels are significantly bowed, you may need to place/park something heavy on the center of your blank prevent you from producing a blank that is 1 ½” on the edges and 1 5/8” in the middle. If you’re using Titebond lll, the open time is pretty short, so plan ahead.


Sent from my iPad using Tapatalk
 

Latest posts

Top