Any tricks for cutting holes for grommet lights

[Iplayfarmer]

In the spirit of totally over-engineering my already over budget and WAY behind schedule trailer remodel, I'm considering adding grommet lights in some sections of 4X3 square tube welded to the sides of the trailer. The tube I have to work with is about 3/16" thick.

Are there any good ways to cut the oval holes for the grommets to fit into? How precise to these holes need to be?

For you Smart Alecs out there with CNC plasma cutters, feel free to tell us how easy it is, but know that we'll be rolling our eyes.

I have a drill press, O/A torch, angle grinder, and a basic assortment of low tech tools.

 

[aczlan]

Hole saw turning VERY slow with oil to lubricate it.

Aaron Z

 

[timswi]

I've done this with an air powered "whizzer wheel" and a die grinder to clean it up...Much patience and many cut-off wheels are required.

 

[Kioti guy]

I use my plasma cutter ( hand not cnc...lol) I have found if you use the light without the rubber grommets as a guide and use a felt marker to trace the shape, then cut the hole to the outside of the felt marker line it fits perfectly every time. If you are pretty good with your torch you should be able to get the the same results as with a plasma just maybe not quite as clean, the grommets are pretty forgiving as long as you are reasonably close.
I'll bet you will be glad to come to the end of this project, nothing worse then starting a small repair job and having it turn into a full time job...good luck ,Craig

 

[Iplayfarmer]

...the grommets are pretty forgiving as long as you are reasonably close...

I was hoping someone would say that. I'll probably do a few practice cuts on a piece of scrap before I go whole hog on the trailer. I'm wondering about the smaller grommets. Would the holes required for the smaller grommets weaken the frame of the trailer? Do I need to build brackets for them if I decide to use them?

 

[gengine]

... I have found if you use the light without the rubber grommets as a guide and use a felt marker to trace the shape, then cut the hole to the outside of the felt marker line it fits perfect every time... ,Craig

I love that idea! I have tried tracing the grommets a couple times as well as using the template that came with the light, neither turned out that great. Thank goodness those grommets are forgiving. They might be a little tight, but they don't fall out,

 

[AKwelder]

i purchased a bracket for each style light i wanted, took it home and used it to trace the hole. i think i paid less than 10 bucks.

for oval holes I found that i could drill the holes with average hole saws and connect it all together with 1/16 inch cut off wheels. Then take an end grinder with a burr or a dressing stone on a regular grinder and clean the inside edge of the holes

On the thin steel i have torched them out but it just seemed to take to long to clean up in the end

Good luck

 

[AKwelder]

i have also learned that a good silicon spray on the grommet makes life much easier.

just not to much

 

[Newblue]

I used a hand plasma cutter and I didn't think it was all that easy! I added two more STT lights and the hardest part to me is getting the holes laid out straight with the current lights. Of course the OCD in me doesn't help . I ended up making them too small and used a die grinder to open them up so the gromets fit.

 

[tlbuser]

After tracing, drill a starter hole then switch to the sawzall with a Lennox Lazer blade.