Choosing the Correct Primer
There are several different types of primers and depending on what you chose will have an impact on the quality of your repair. Here are a few terms to be familiar with & a few choices.
1 or 2K ?
This just means it requires an activator. 2K products require a hardener to be added before use where a 1K does not. 2K products on a generalization are always your best choice. They will cross link which makes your finished film a giant molecule that is more durable then a 1k product.
Primer vs Primer Surfacer
Primers are usually applied as a pre-treatment under a primer surfacer. A primer you don\’t sand after applying, a primer surfacer is designed to fill and will be sanded after drying.
For the best protection most people will turn to an epoxy primer before applying a urethane filler. Some people swear by etch primer & others will simply use a direct to metal urethane primer. Anything you chose will work, it all depends on the level of comfort you are after.
|Etch primers come in two styles. 1k & 2k. 2K is the preferred choice if using an etch. It is used only on the bare metal underneath of a primer surfacer.|
|Epoxy primers are usually considered the best of the best. They will only come in the 2K form. They offer fantastic metal protection and durability. They are usually applied under your primer surfacer. Some epoxy\’s you can use as a surfacer, however they do not sand very well compared to urethane based surfacers.|
|Many people refer to this as 2K primer (despite the fact many other products are 2 part). Urethane primers generally only come as primer surfacers designed to fill. They also come in regular or direct to metal (DTM), which simply means it does not require an etch or epoxy primer be applied first. A DTM is your best choice if you want a 1 step application, however the quality won\’t be as high as if you were to apply an epoxy primer first.|
|Polyester primers are severally high building primer surfacers. They can be used prior to using a urethane surfacer. This kind of product is often used on larger restoration jobs when trying to get a larger area very straight. its like a spray putty but sands easier.|