FAQ putty

How can the filler be diluted?
The filler can be diluted at any ratio with polyester resin. We offer this product in two different versions, once under article no. 600429 as a 250g package and once under article no. 600528 as a 1000g package. The texture can then be chosen at will. However, 15% additive are already sufficient for the filler to be  made flowable. Product properties like pot life, adhesion or grindability of the filler do not change as a result.

The resin fails to properly harden, it remains sticky. What can be done about this?
A sticky surface remains after hardening of the resin from the repair box and of the product repair resin. This is intended because it serves as a bonding bridge for further filler construction. If, for whatever reasons, one does not wish to undertake further construction then the surface adhesive can be removed by dilution. This should absolutely also be done since, otherwise, the surface may attract dirt and can very quickly appear unattractive.

How heat-resistant is the filler mass?
Our two component polyester fillers are heat-resistant up to 120°C. An exception is the prestolith easy fine grade filler, article no. 601457 is an exception. Easy is heat-resistant up to 180°C. This question often arises in connection with the question concerning a filler which is suitable for the repair for powder coatings. In this case, only prestolith easy is to be recommended, because temperatures around 180° C are generated during the coating process.
The single-component presto finish NC combination filler, just like our varnishes, is heat-resistant up to 80°C.


The product is past the expiration date. Can the filler still be used?
We guarantee a two-year shelf life for the filler masses. If the filler is stored at temperatures around 20 °C, we know that storage stability times of 3.5 to 4 years are possible.
If the hardener and filler masses have not been mixed by the time the expiration date has passed, the reaction takes place in any event, i.e. the filler masses will harden even without adding the hardener, with the same properties as the fresh product.

What is the meaning of: 2 component polyester filler?
The products are made up of two components: a filler mass and a hardener. There is hardener atop of each can and this has been precisely weighed according to filler quantity. Optimum dosage is 2.5% proportional to the filler. As a catalyst, the hardener sets off the hardening reaction. For this, there must be even through-mixing of hardener and filler mass.
The name polyester is derived from the binders that give the materials their respective properties. Unsaturated polyester resins cross-link during the reaction and, therefore, largely make up both hardness and stability of the filler.

What does prestolith actually mean?
prestomeansfastandlithis derived from the work lithos, which meansstone, i.e. material hardens quickly and becomes stone-solid.

How long is the processing time of filler mass?
Processing time depends on processing temperature. If we say: processing time is 4 minutes, this refers to an ambient temperature of 20 degrees Celsius. If one processed the same filler at 30 degrees Celsius, the processing time would be just about 2 min. and/or at 10 degrees Celsius, it would then be 8 minutes.
Filler should not be processed below a temperature of 10 degrees Celsius since it becomes too brittle then and there is no more ductility.
The filler mass is designed for a processing time of about 4 minutes. The resins are designed for about 10 minutes since, here, the application process takes considerably longer. With the new, blue hardener, this processing time can be extended to 6 minutes.

What is an exothermal reaction?
An exothermal reaction takes place during hardening of 2 component polyester, i.e. the material may heat up to temperatures of 110 °C. However, these kinds of temperatures will only result once processing time is over. Hence, there is no need for the user to fear burning his or her hands. Maximum temperatures, however, are only ever reached if filling takes place in thick layers or blocks. If filler layer thickness is low, the heat quickly dissipates through the sheet metal and the air.
An exothermal reaction is one of the fastest reactions we know of in chemistry. Heat emission finally also means the emission of energy so that the filler, following hardening, is at a much lower energy level and, therefore, cannot be dissolved again through anything else but heat. Temperature limits for all filler masses are at 120°C, with exception of the prestolith easy fine grade filler, which can withstand temperatures of up to 180°C and is therefore also suitable for powder coatings.

What exactly does the hardener do?
Without addition of hardener, polyester fillers or resins remain liquid and/or "pasty". The polyester reaction is only activated once approx. 2-4 % hardener is added and then the polyester hardens within a matter of minutes. Once the hardener has been added, it is no longer possible to stop the hardening process. For this reason, only the quantity required is ever actually mixed, and no mixed material must be returned to the can. The rest of the can would be rendered useless through this. The chemical reaction of hardening leads to material heating during processing.

Why is the supplied hardener for all fillers stained red?
The hardener is stained red so that the processor can see whether enough hardener has been added and whether the mass has been properly (streak-free) been mixed through (meaning homogeneously). Here, too, the advantage of our products becomes evident: Our hardener is self-decolourising This means that the dye in the hardener dissolves after a short time and the filler does not retain a pink tinge but re-assumes the colour that it had prior to the reaction.

Can filler be stained?
Principally, it is possible to stain  the filler mass. However, this is only possible by using special polyester colour pastes. These colour pastes are available through well stocked hobby specialty stores.


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