No you can't. Tradeable through fusing means you only get the image of the one you want to fuse with the stats of the base item.
Let's say I have a Silpheed Gun which in untradeable. I want to fuse it to become tradeable so I have to fuse it with any tradeable gun. But of course the stats of the Silpheed Gun won't be transferred.
To further explain it to you:
Image Item: Silpheed Gun
Stats Item: Wood Gun
This means that if I fuse these, I will get a Wood Gun that looks like a Silpheed Gun. Or if you interchanged it:
Image Item: Wood Gun
Stats Item: Silpheed Gun
You will get a Silpheed Gun that looks like a Wood Gun.
This also applies to pets. Some of the reasons why people fuse is because they want their equips to look good and some just fuse to sell it to people.