Pre drill transom or not?

[TOY BOAT]

So tomorrow, I will be replacing my first transom. The one I just removed was encased with aluminum, and bolted in. I assume it has been replaced at some point. Not a 100% sure. Either way, I am concerned that drilling once installed, I may miss the hole on the other side, and not hit everyone exactly. I was thinking of pre drilling every hole with one size bigger bit before installing. Which would be better? Pre drill with bigger bit on the wood only, or wait till the transom is in place, and try drilling through?
Also, there is the two splash well drains. I can get them easy enough. But how do I crimp it once I have it?

Thanks

At the end of this build, I should be able to give advise.

 

[See Chris Fish]

I'd drill after install. Use a small bit on the first pass. You can adjust location accordingly. Good luck. Keep us informed.

 

[TOY BOAT]

I'd drill after install. Use a small bit on the first pass. You can adjust location accordingly. Good luck. Keep us informed.

Thank you. That certainly makes sense. I did not like the idea of predrilling other than I could get spar urethane in the holes to protect the wood after drilling. I like the small bit idea. =D>

 

[Ringo Steele]

Just do a dry fit if feasible. Drill your holes then, then remove the wood and re-size and seal the holes with the spar.

 

[fishinnut]

What I did when I replaced my transom was to build a drilling template. I used cutoffs from the 1 1/2 inch transom but you could use scrap 2x4's. Prior to placing transom clamp a 2x4 on the outside over hole/holes. Mark the 2x4 so that it can be placed in the same location once the transom boar is placed. Drill with appropriate size bit from the inside and thru the 2x4. You now have the correct angle for the hole. Just reclamp the 2x4 and start drilling thru 2x4 into transom. Make a template for all the holes.