Metallurgy question

Prepping new traps for paint dip. Etching with a phosphoric acid based product. Will it weaken springs?
Older rusty traps?

I know some use Muriatic which is hydrochloric and I don't read of it.

i wouldn't use any acid stronger than vinegar, the acid could get in the springs and just keep eating .

Some acids could be neutralized in baking soda. But like cotton sais id just use vinegar

The key to using an acid is neutralizing it when you are finished. Muriatic acid is great, but seconds matter. Have a bucket of baking soda solution to neutralize the acid and also your skin in case of contact. Really slosh it in the baking soda to get in all the coils in the springs. I don’t use vinegar only because muriatic acid is much faster. Vinegar is safer however. Also aluminum will be destroyed in very short order so keep all ferrels out of the acid.

When we were kids we used Coke to clean rust off Cone Top beer cans we found in the dump- Coke contains Phosphoric Acid., Phosphoric Acid (H3P04) is a weaker acid on a comparable scale to other acids and if neutralized properly will not weaken your springs. I'm not sure how much rust you have but Phosphoric Acid doesn't really remove rust - it will convert the rust to Ferric Phosphate, this is where the plating term, Phosphating comes from. Acids need to be neutralized with a base to make them not only safe but to stop the chemical action and reaction, I would rinse the traps off in clean water and then dip them in a bucket with diluted alkaline to neutralize the acid, either ammonia or dish soap would be a good choice. Baking Soda might be another option for neutralizing the acid. Hope that helps.

50-50 vinegar-water
I wire 6-8 traps together
Soak 1 day and flip em over for another day
Pressure wash at car wash 1 cycle soap then 2nd cycle clean water, flipping them bout every 30-40 seconds during both cycles.
Come out looking like new.

It's not a whole lot of work to remove and reinstall coil springs.

Used hcl for years with no problems. Then I soaked a particular brand of bg trap, and about half the springs snapped, as in broke.