I started with the heat it with a torch type, and never got the time versus temp part down, and it was very inconsistent. Moved on to a really cheap electric, and it was a step better, but the heating portion was also cheap, and it was still pretty wide in range of effectiveness. Moved to a really well made custom one, cost over a hunnert bux, but I plug it in, set my little timer deal I use for timing glueups. Anyhow 15 minutes, and I can brand any wood, and get spectacular results. Experience had taught me Cherry, and SOFT Maple, I don't push down much at all, and it is great, if I press it they both burn really easily, and it sort of mars the brand, You can still see it, but it is notable.

There are a few peeps in the game of making them, but I was at a woodworking show where I believe all of them attended, and the guy I ended up buying from was the one at the show who showed far and away he was willing to work with you. I didn't have artwork at that time, but my idea was simple. I wanted a tree shape, and my name below in a easily readable font. Terry sent me over 60 looks, to see what I wanted, so deciding was right there, and I was really happy. My brand is bigger, and he suggested an upcharge heating element to make sure the brands are consistent. All I know is except for the 2 woods I know to be really burners, all others, including pine come out like a good engraver did them. Anyhow my guy is  Terry Desilets, and his company is Custom Branding irons My Wife makes baskets, she gifts, and sells them, and brands her work, Terry worked with her to get the perfect brand, and she is a bigger cheerleader for him than I am. 

So my contribution is this. No matter what you get, before you brand, take a piece of scrap from your project, and brand that first. If you like it, proceed. If not, well adding more time to heat if electric, or longer heat if it's a torcher would be my guess, but if you just can't get it done? I know from experience Terry can help you out. Price WILL be more than a junker. But always practice before you play, and because I have identified woods that brand differently, you will no doubt see a little variation. Better to see it on a piece of scrap, than a project you spent time on making.